diff --git a/ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/math/Round.java b/ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/math/Round.java
index 0fc8681075a1..2973abc37489 100644
--- a/ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/math/Round.java
+++ b/ksqldb-engine/src/main/java/io/confluent/ksql/function/udf/math/Round.java
@@ -62,6 +62,7 @@ in order to provide compatibility with the previous ROUND() implementation which
 we need to use different rounding modes on BigDecimal depending on whether the value
 is +ve or -ve to get consistent behaviour.
 */
+@SuppressWarnings("MethodMayBeStatic")
 @UdfDescription(
     name = "Round",
     category = FunctionCategory.MATHEMATICAL,
@@ -100,7 +101,10 @@ public Double round(@UdfParameter final Double val, @UdfParameter final Integer
 
   @Udf(schemaProvider = "provideDecimalSchema")
   public BigDecimal round(@UdfParameter final BigDecimal val) {
-    return round(val, 0);
+    if (val == null) {
+      return null;
+    }
+    return roundBigDecimal(val, 0);
   }
 
   @Udf(schemaProvider = "provideDecimalSchemaWithDecimalPlaces")
@@ -108,11 +112,17 @@ public BigDecimal round(
       @UdfParameter final BigDecimal val,
       @UdfParameter final Integer decimalPlaces
   ) {
-    return val == null ? null : roundBigDecimal(val, decimalPlaces);
+    if (val == null) {
+      return null;
+    }
+    return roundBigDecimal(val, decimalPlaces)
+        // Must maintain source scale for now. See https://github.com/confluentinc/ksql/issues/6235.
+        .setScale(val.scale(), RoundingMode.UNNECESSARY);
   }
 
+  @SuppressWarnings("unused") // Invoked via reflection
   @UdfSchemaProvider
-  public SqlType provideDecimalSchemaWithDecimalPlaces(final List<SqlType> params) {
+  public static SqlType provideDecimalSchemaWithDecimalPlaces(final List<SqlType> params) {
     final SqlType s0 = params.get(0);
     if (s0.baseType() != SqlBaseType.DECIMAL) {
       throw new KsqlException("The schema provider method for round expects a BigDecimal parameter"
@@ -123,11 +133,15 @@ public SqlType provideDecimalSchemaWithDecimalPlaces(final List<SqlType> params)
       throw new KsqlException("The schema provider method for round expects an Integer parameter"
           + "type as second parameter.");
     }
+
+    // While the user requested a certain number of decimal places, this can't be used to change
+    // the scale of the return type. See https://github.com/confluentinc/ksql/issues/6235.
     return s0;
   }
 
+  @SuppressWarnings("unused") // Invoked via reflection
   @UdfSchemaProvider
-  public SqlType provideDecimalSchema(final List<SqlType> params) {
+  public static SqlType provideDecimalSchema(final List<SqlType> params) {
     final SqlType s0 = params.get(0);
     if (s0.baseType() != SqlBaseType.DECIMAL) {
       throw new KsqlException("The schema provider method for round expects a BigDecimal parameter"
@@ -137,7 +151,10 @@ public SqlType provideDecimalSchema(final List<SqlType> params) {
     return SqlDecimal.of(param.getPrecision() - param.getScale(), 0);
   }
 
-  private BigDecimal roundBigDecimal(final BigDecimal val, final int decimalPlaces) {
+  private static BigDecimal roundBigDecimal(
+      final BigDecimal val,
+      final int decimalPlaces
+  ) {
     final RoundingMode roundingMode = val.compareTo(BigDecimal.ZERO) > 0
         ? RoundingMode.HALF_UP : RoundingMode.HALF_DOWN;
     return val.setScale(decimalPlaces, roundingMode);
diff --git a/ksqldb-engine/src/test/java/io/confluent/ksql/function/udf/math/RoundTest.java b/ksqldb-engine/src/test/java/io/confluent/ksql/function/udf/math/RoundTest.java
index c91b2e5463c3..a484c7fec874 100644
--- a/ksqldb-engine/src/test/java/io/confluent/ksql/function/udf/math/RoundTest.java
+++ b/ksqldb-engine/src/test/java/io/confluent/ksql/function/udf/math/RoundTest.java
@@ -152,67 +152,66 @@ public void shouldRoundDoubleWithDecimalPlacesNegative() {
   @Test
   public void shouldRoundBigDecimalWithDecimalPlacesPositive() {
     assertThat(udf.round(new BigDecimal("0"), 0), is(new BigDecimal("0")));
-    assertThat(udf.round(new BigDecimal("1.0"), 0), is(new BigDecimal("1")));
-    assertThat(udf.round(new BigDecimal("1.1"), 0), is(new BigDecimal("1")));
-    assertThat(udf.round(new BigDecimal("1.5"), 0), is(new BigDecimal("2")));
-    assertThat(udf.round(new BigDecimal("1.75"), 0), is(new BigDecimal("2")));
-    assertThat(udf.round(new BigDecimal("100.1"), 0),is(new BigDecimal("100")));
-    assertThat(udf.round(new BigDecimal("100.5"), 0), is(new BigDecimal("101")));
-    assertThat(udf.round(new BigDecimal("100.75"), 0), is(new BigDecimal("101")));
-    assertThat(udf.round(new BigDecimal("100.10"), 1), is(new BigDecimal("100.1")));
-    assertThat(udf.round(new BigDecimal("100.11"), 1), is(new BigDecimal("100.1")));
-    assertThat(udf.round(new BigDecimal("100.15"), 1), is(new BigDecimal("100.2")));
-    assertThat(udf.round(new BigDecimal("100.17"), 1), is(new BigDecimal("100.2")));
-    assertThat(udf.round(new BigDecimal("100.110"), 2), is(new BigDecimal("100.11")));
-    assertThat(udf.round(new BigDecimal("100.111"), 2), is(new BigDecimal("100.11")));
-    assertThat(udf.round(new BigDecimal("100.115"), 2), is(new BigDecimal("100.12")));
-    assertThat(udf.round(new BigDecimal("100.117"), 2), is(new BigDecimal("100.12")));
-    assertThat(udf.round(new BigDecimal("100.1110"), 3), is(new BigDecimal("100.111")));
-    assertThat(udf.round(new BigDecimal("100.1111"), 3), is(new BigDecimal("100.111")));
-    assertThat(udf.round(new BigDecimal("100.1115"), 3), is(new BigDecimal("100.112")));
-    assertThat(udf.round(new BigDecimal("100.1117"), 3), is(new BigDecimal("100.112")));
-    assertThat(udf.round(new BigDecimal("12345.67"), -1), is(new BigDecimal("1.235E4")));
-    assertThat(udf.round(new BigDecimal("12345.67"), -2), is(new BigDecimal("1.23E4")));
-    assertThat(udf.round(new BigDecimal("12345.67"), -3), is(new BigDecimal("1.2E4")));
-    assertThat(udf.round(new BigDecimal("12345.67"), -4), is(new BigDecimal("1E4")));
-    assertThat(udf.round(new BigDecimal("12345.67"), -5), is(new BigDecimal("0E5")));
+    assertThat(udf.round(new BigDecimal("1.0"), 0), is(new BigDecimal("1.0")));
+    assertThat(udf.round(new BigDecimal("1.1"), 0), is(new BigDecimal("1.0")));
+    assertThat(udf.round(new BigDecimal("1.5"), 0), is(new BigDecimal("2.0")));
+    assertThat(udf.round(new BigDecimal("1.75"), 0), is(new BigDecimal("2.00")));
+    assertThat(udf.round(new BigDecimal("100.1"), 0),is(new BigDecimal("100.0")));
+    assertThat(udf.round(new BigDecimal("100.5"), 0), is(new BigDecimal("101.0")));
+    assertThat(udf.round(new BigDecimal("100.75"), 0), is(new BigDecimal("101.00")));
+    assertThat(udf.round(new BigDecimal("100.10"), 1), is(new BigDecimal("100.10")));
+    assertThat(udf.round(new BigDecimal("100.11"), 1), is(new BigDecimal("100.10")));
+    assertThat(udf.round(new BigDecimal("100.15"), 1), is(new BigDecimal("100.20")));
+    assertThat(udf.round(new BigDecimal("100.17"), 1), is(new BigDecimal("100.20")));
+    assertThat(udf.round(new BigDecimal("100.110"), 2), is(new BigDecimal("100.110")));
+    assertThat(udf.round(new BigDecimal("100.111"), 2), is(new BigDecimal("100.110")));
+    assertThat(udf.round(new BigDecimal("100.115"), 2), is(new BigDecimal("100.120")));
+    assertThat(udf.round(new BigDecimal("100.117"), 2), is(new BigDecimal("100.120")));
+    assertThat(udf.round(new BigDecimal("100.1110"), 3), is(new BigDecimal("100.1110")));
+    assertThat(udf.round(new BigDecimal("100.1111"), 3), is(new BigDecimal("100.1110")));
+    assertThat(udf.round(new BigDecimal("100.1115"), 3), is(new BigDecimal("100.1120")));
+    assertThat(udf.round(new BigDecimal("100.1117"), 3), is(new BigDecimal("100.1120")));
+    assertThat(udf.round(new BigDecimal("12345.67"), -1), is(new BigDecimal("12350.00")));
+    assertThat(udf.round(new BigDecimal("12345.67"), -2), is(new BigDecimal("12300.00")));
+    assertThat(udf.round(new BigDecimal("12345.67"), -3), is(new BigDecimal("12000.00")));
+    assertThat(udf.round(new BigDecimal("12345.67"), -4), is(new BigDecimal("10000.00")));
+    assertThat(udf.round(new BigDecimal("12345.67"), -5), is(new BigDecimal("0.00")));
   }
 
   @Test
   public void shouldRoundBigDecimalWithDecimalPlacesNegative() {
-    assertThat(udf.round(new BigDecimal("-1.0"), 0), is(new BigDecimal("-1")));
-    assertThat(udf.round(new BigDecimal("-1.1"), 0), is(new BigDecimal("-1")));
-    assertThat(udf.round(new BigDecimal("-1.5"), 0), is(new BigDecimal("-1")));
-    assertThat(udf.round(new BigDecimal("-1.75"), 0), is(new BigDecimal("-2")));
-    assertThat(udf.round(new BigDecimal("-100.1"), 0), is(new BigDecimal("-100")));
-    assertThat(udf.round(new BigDecimal("-100.5"), 0), is(new BigDecimal("-100")));
-    assertThat(udf.round(new BigDecimal("-100.75"), 0), is(new BigDecimal("-101")));
-    assertThat(udf.round(new BigDecimal("-100.10"), 1), is(new BigDecimal("-100.1")));
-    assertThat(udf.round(new BigDecimal("-100.11"), 1), is(new BigDecimal("-100.1")));
-    assertThat(udf.round(new BigDecimal("-100.15"), 1), is(new BigDecimal("-100.1")));
-    assertThat(udf.round(new BigDecimal("-100.17"), 1), is(new BigDecimal("-100.2")));
-    assertThat(udf.round(new BigDecimal("-100.110"), 2), is(new BigDecimal("-100.11")));
-    assertThat(udf.round(new BigDecimal("-100.111"), 2), is(new BigDecimal("-100.11")));
-    assertThat(udf.round(new BigDecimal("-100.115"), 2), is(new BigDecimal("-100.11")));
-    assertThat(udf.round(new BigDecimal("-100.117"), 2), is(new BigDecimal("-100.12")));
-    assertThat(udf.round(new BigDecimal("-100.1110"), 3), is(new BigDecimal("-100.111")));
-    assertThat(udf.round(new BigDecimal("-100.1111"), 3), is(new BigDecimal("-100.111")));
-    assertThat(udf.round(new BigDecimal("-100.1115"), 3), is(new BigDecimal("-100.111")));
-    assertThat(udf.round(new BigDecimal("-100.1117"), 3), is(new BigDecimal("-100.112")));
-    assertThat(udf.round(new BigDecimal("-12345.67"), -1), is(new BigDecimal("-1.235E4")));
-    assertThat(udf.round(new BigDecimal("-12345.67"), -2), is(new BigDecimal("-1.23E4")));
-    assertThat(udf.round(new BigDecimal("-12345.67"), -3), is(new BigDecimal("-1.2E4")));
-    assertThat(udf.round(new BigDecimal("-12345.67"), -4), is(new BigDecimal("-1E4")));
-    assertThat(udf.round(new BigDecimal("-12345.67"), -5), is(new BigDecimal("-0E5")));
+    assertThat(udf.round(new BigDecimal("-1.0"), 0), is(new BigDecimal("-1.0")));
+    assertThat(udf.round(new BigDecimal("-1.1"), 0), is(new BigDecimal("-1.0")));
+    assertThat(udf.round(new BigDecimal("-1.5"), 0), is(new BigDecimal("-1.0")));
+    assertThat(udf.round(new BigDecimal("-1.75"), 0), is(new BigDecimal("-2.00")));
+    assertThat(udf.round(new BigDecimal("-100.1"), 0), is(new BigDecimal("-100.0")));
+    assertThat(udf.round(new BigDecimal("-100.5"), 0), is(new BigDecimal("-100.0")));
+    assertThat(udf.round(new BigDecimal("-100.75"), 0), is(new BigDecimal("-101.00")));
+    assertThat(udf.round(new BigDecimal("-100.10"), 1), is(new BigDecimal("-100.10")));
+    assertThat(udf.round(new BigDecimal("-100.11"), 1), is(new BigDecimal("-100.10")));
+    assertThat(udf.round(new BigDecimal("-100.15"), 1), is(new BigDecimal("-100.10")));
+    assertThat(udf.round(new BigDecimal("-100.17"), 1), is(new BigDecimal("-100.20")));
+    assertThat(udf.round(new BigDecimal("-100.110"), 2), is(new BigDecimal("-100.110")));
+    assertThat(udf.round(new BigDecimal("-100.111"), 2), is(new BigDecimal("-100.110")));
+    assertThat(udf.round(new BigDecimal("-100.115"), 2), is(new BigDecimal("-100.110")));
+    assertThat(udf.round(new BigDecimal("-100.117"), 2), is(new BigDecimal("-100.120")));
+    assertThat(udf.round(new BigDecimal("-100.1110"), 3), is(new BigDecimal("-100.1110")));
+    assertThat(udf.round(new BigDecimal("-100.1111"), 3), is(new BigDecimal("-100.1110")));
+    assertThat(udf.round(new BigDecimal("-100.1115"), 3), is(new BigDecimal("-100.1110")));
+    assertThat(udf.round(new BigDecimal("-100.1117"), 3), is(new BigDecimal("-100.1120")));
+    assertThat(udf.round(new BigDecimal("-12345.67"), -2), is(new BigDecimal("-12300.00")));
+    assertThat(udf.round(new BigDecimal("-12345.67"), -3), is(new BigDecimal("-12000.00")));
+    assertThat(udf.round(new BigDecimal("-12345.67"), -4), is(new BigDecimal("-10000.00")));
+    assertThat(udf.round(new BigDecimal("-12345.67"), -5), is(new BigDecimal("0.00")));
   }
 
   @Test
-  public void shouldHandleDoubleLiteralsEndingWith5ThatCannotBeRepresentedExactylyAsDoubles() {
-    assertThat(udf.round(new BigDecimal("265.335"), 2), is(new BigDecimal("265.34")));
-    assertThat(udf.round(new BigDecimal("-265.335"), 2), is(new BigDecimal("-265.33")));
+  public void shouldHandleDoubleLiteralsEndingWith5ThatCannotBeRepresentedExactlyAsDoubles() {
+    assertThat(udf.round(new BigDecimal("265.335"), 2), is(new BigDecimal("265.340")));
+    assertThat(udf.round(new BigDecimal("-265.335"), 2), is(new BigDecimal("-265.330")));
 
-    assertThat(udf.round(new BigDecimal("265.365"), 2), is(new BigDecimal("265.37")));
-    assertThat(udf.round(new BigDecimal("-265.365"), 2), is(new BigDecimal("-265.36")));
+    assertThat(udf.round(new BigDecimal("265.365"), 2), is(new BigDecimal("265.370")));
+    assertThat(udf.round(new BigDecimal("-265.365"), 2), is(new BigDecimal("-265.360")));
   }
 
   @Test
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/plan.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/plan.json
new file mode 100644
index 000000000000..65d173f5995f
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/plan.json
@@ -0,0 +1,140 @@
+{
+  "plan" : [ {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM TEST (ID STRING KEY, V DECIMAL(33, 16)) WITH (KAFKA_TOPIC='test_topic', VALUE_FORMAT='AVRO');",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "TEST",
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "topicName" : "test_topic",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "AVRO"
+        }
+      },
+      "orReplace" : false
+    }
+  }, {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM OUTPUT AS SELECT\n  TEST.ID ID,\n  ROUND(TEST.V) R0,\n  ROUND(TEST.V, 0) R00\nFROM TEST TEST\nEMIT CHANGES",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "OUTPUT",
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+      "topicName" : "OUTPUT",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "AVRO"
+        }
+      },
+      "orReplace" : false
+    },
+    "queryPlan" : {
+      "sources" : [ "TEST" ],
+      "sink" : "OUTPUT",
+      "physicalPlan" : {
+        "@type" : "streamSinkV1",
+        "properties" : {
+          "queryContext" : "OUTPUT"
+        },
+        "source" : {
+          "@type" : "streamSelectV1",
+          "properties" : {
+            "queryContext" : "Project"
+          },
+          "source" : {
+            "@type" : "streamSourceV1",
+            "properties" : {
+              "queryContext" : "KsqlTopic/Source"
+            },
+            "topicName" : "test_topic",
+            "formats" : {
+              "keyFormat" : {
+                "format" : "KAFKA"
+              },
+              "valueFormat" : {
+                "format" : "AVRO"
+              }
+            },
+            "sourceSchema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)"
+          },
+          "keyColumnNames" : [ "ID" ],
+          "selectExpressions" : [ "ROUND(V) AS R0", "ROUND(V, 0) AS R00" ]
+        },
+        "formats" : {
+          "keyFormat" : {
+            "format" : "KAFKA"
+          },
+          "valueFormat" : {
+            "format" : "AVRO"
+          }
+        },
+        "topicName" : "OUTPUT"
+      },
+      "queryId" : "CSAS_OUTPUT_0"
+    }
+  } ],
+  "configs" : {
+    "ksql.extension.dir" : "ext",
+    "ksql.streams.cache.max.bytes.buffering" : "0",
+    "ksql.security.extension.class" : null,
+    "metric.reporters" : "",
+    "ksql.transient.prefix" : "transient_",
+    "ksql.query.status.running.threshold.seconds" : "300",
+    "ksql.streams.default.deserialization.exception.handler" : "io.confluent.ksql.errors.LogMetricAndContinueExceptionHandler",
+    "ksql.output.topic.name.prefix" : "",
+    "ksql.query.pull.enable.standby.reads" : "false",
+    "ksql.streams.max.task.idle.ms" : "0",
+    "ksql.query.error.max.queue.size" : "10",
+    "ksql.internal.topic.min.insync.replicas" : "1",
+    "ksql.streams.shutdown.timeout.ms" : "300000",
+    "ksql.internal.topic.replicas" : "1",
+    "ksql.insert.into.values.enabled" : "true",
+    "ksql.query.pull.max.allowed.offset.lag" : "9223372036854775807",
+    "ksql.query.pull.max.qps" : "2147483647",
+    "ksql.access.validator.enable" : "auto",
+    "ksql.streams.bootstrap.servers" : "localhost:0",
+    "ksql.query.pull.metrics.enabled" : "false",
+    "ksql.create.or.replace.enabled" : "true",
+    "ksql.metrics.extension" : null,
+    "ksql.hidden.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.cast.strings.preserve.nulls" : "true",
+    "ksql.authorization.cache.max.entries" : "10000",
+    "ksql.pull.queries.enable" : "true",
+    "ksql.suppress.enabled" : "false",
+    "ksql.sink.window.change.log.additional.retention" : "1000000",
+    "ksql.readonly.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.query.persistent.active.limit" : "2147483647",
+    "ksql.persistence.wrap.single.values" : null,
+    "ksql.authorization.cache.expiry.time.secs" : "30",
+    "ksql.query.retry.backoff.initial.ms" : "15000",
+    "ksql.schema.registry.url" : "",
+    "ksql.properties.overrides.denylist" : "",
+    "ksql.streams.auto.offset.reset" : "earliest",
+    "ksql.connect.url" : "http://localhost:8083",
+    "ksql.service.id" : "some.ksql.service.id",
+    "ksql.streams.default.production.exception.handler" : "io.confluent.ksql.errors.ProductionExceptionHandlerUtil$LogAndFailProductionExceptionHandler",
+    "ksql.enable.metastore.backup" : "false",
+    "ksql.streams.commit.interval.ms" : "2000",
+    "ksql.streams.auto.commit.interval.ms" : "0",
+    "ksql.streams.topology.optimization" : "all",
+    "ksql.query.retry.backoff.max.ms" : "900000",
+    "ksql.streams.num.stream.threads" : "4",
+    "ksql.timestamp.throw.on.invalid" : "false",
+    "ksql.metrics.tags.custom" : "",
+    "ksql.udfs.enabled" : "true",
+    "ksql.udf.enable.security.manager" : "true",
+    "ksql.connect.worker.config" : "",
+    "ksql.udf.collect.metrics" : "false",
+    "ksql.persistent.prefix" : "query_",
+    "ksql.metastore.backup.location" : "",
+    "ksql.error.classifier.regex" : "",
+    "ksql.suppress.buffer.size.bytes" : "-1"
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/spec.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/spec.json
new file mode 100644
index 000000000000..867474d41652
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/spec.json
@@ -0,0 +1,110 @@
+{
+  "version" : "6.1.0",
+  "timestamp" : 1600280487284,
+  "path" : "query-validation-tests/math.json",
+  "schemas" : {
+    "CSAS_OUTPUT_0.KsqlTopic.Source" : {
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    },
+    "CSAS_OUTPUT_0.OUTPUT" : {
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    }
+  },
+  "testCase" : {
+    "name" : "round with large DECIMAL values - AVRO",
+    "inputs" : [ {
+      "topic" : "test_topic",
+      "key" : null,
+      "value" : {
+        "v" : 12345678987654321.2345678987654321
+      }
+    } ],
+    "outputs" : [ {
+      "topic" : "OUTPUT",
+      "key" : null,
+      "value" : {
+        "R0" : 12345678987654321,
+        "R00" : 12345678987654321.0000000000000000
+      }
+    } ],
+    "topics" : [ {
+      "name" : "OUTPUT",
+      "replicas" : 1,
+      "numPartitions" : 4
+    }, {
+      "name" : "test_topic",
+      "schema" : {
+        "type" : "record",
+        "name" : "KsqlDataSourceSchema",
+        "namespace" : "io.confluent.ksql.avro_schemas",
+        "fields" : [ {
+          "name" : "V",
+          "type" : [ "null", {
+            "type" : "bytes",
+            "scale" : 16,
+            "precision" : 33,
+            "connect.version" : 1,
+            "connect.parameters" : {
+              "scale" : "16",
+              "connect.decimal.precision" : "33"
+            },
+            "connect.name" : "org.apache.kafka.connect.data.Decimal",
+            "logicalType" : "decimal"
+          } ],
+          "default" : null
+        } ],
+        "connect.name" : "io.confluent.ksql.avro_schemas.KsqlDataSourceSchema"
+      },
+      "format" : "AVRO",
+      "replicas" : 1,
+      "numPartitions" : 4
+    } ],
+    "statements" : [ "CREATE STREAM test (ID STRING KEY, v DECIMAL(33, 16)) WITH (kafka_topic='test_topic', value_format='AVRO');", "CREATE STREAM OUTPUT AS SELECT ID, ROUND(v) as R0, ROUND(v, 0) as R00 FROM test;" ],
+    "post" : {
+      "sources" : [ {
+        "name" : "OUTPUT",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      }, {
+        "name" : "TEST",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      } ],
+      "topics" : {
+        "topics" : [ {
+          "name" : "test_topic",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "AVRO"
+          },
+          "partitions" : 4
+        }, {
+          "name" : "OUTPUT",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "AVRO"
+          },
+          "partitions" : 4
+        } ]
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/topology b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/topology
new file mode 100644
index 000000000000..441a8f282644
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_AVRO/6.1.0_1600280487284/topology
@@ -0,0 +1,13 @@
+Topologies:
+   Sub-topology: 0
+    Source: KSTREAM-SOURCE-0000000000 (topics: [test_topic])
+      --> KSTREAM-TRANSFORMVALUES-0000000001
+    Processor: KSTREAM-TRANSFORMVALUES-0000000001 (stores: [])
+      --> Project
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: Project (stores: [])
+      --> KSTREAM-SINK-0000000003
+      <-- KSTREAM-TRANSFORMVALUES-0000000001
+    Sink: KSTREAM-SINK-0000000003 (topic: OUTPUT)
+      <-- Project
+
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/plan.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/plan.json
new file mode 100644
index 000000000000..7a98af0461f4
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/plan.json
@@ -0,0 +1,140 @@
+{
+  "plan" : [ {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM TEST (ID STRING KEY, V DECIMAL(33, 16)) WITH (KAFKA_TOPIC='test_topic', VALUE_FORMAT='DELIMITED');",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "TEST",
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "topicName" : "test_topic",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "DELIMITED"
+        }
+      },
+      "orReplace" : false
+    }
+  }, {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM OUTPUT AS SELECT\n  TEST.ID ID,\n  ROUND(TEST.V) R0,\n  ROUND(TEST.V, 0) R00,\n  ROUND(TEST.V, 1) R1,\n  ROUND(TEST.V, 2) R2,\n  ROUND(TEST.V, 10) R10,\n  ROUND(TEST.V, -1) 1R,\n  ROUND(TEST.V, -2) 2R\nFROM TEST TEST\nEMIT CHANGES",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "OUTPUT",
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16), `R1` DECIMAL(33, 16), `R2` DECIMAL(33, 16), `R10` DECIMAL(33, 16), `1R` DECIMAL(33, 16), `2R` DECIMAL(33, 16)",
+      "topicName" : "OUTPUT",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "DELIMITED"
+        }
+      },
+      "orReplace" : false
+    },
+    "queryPlan" : {
+      "sources" : [ "TEST" ],
+      "sink" : "OUTPUT",
+      "physicalPlan" : {
+        "@type" : "streamSinkV1",
+        "properties" : {
+          "queryContext" : "OUTPUT"
+        },
+        "source" : {
+          "@type" : "streamSelectV1",
+          "properties" : {
+            "queryContext" : "Project"
+          },
+          "source" : {
+            "@type" : "streamSourceV1",
+            "properties" : {
+              "queryContext" : "KsqlTopic/Source"
+            },
+            "topicName" : "test_topic",
+            "formats" : {
+              "keyFormat" : {
+                "format" : "KAFKA"
+              },
+              "valueFormat" : {
+                "format" : "DELIMITED"
+              }
+            },
+            "sourceSchema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)"
+          },
+          "keyColumnNames" : [ "ID" ],
+          "selectExpressions" : [ "ROUND(V) AS R0", "ROUND(V, 0) AS R00", "ROUND(V, 1) AS R1", "ROUND(V, 2) AS R2", "ROUND(V, 10) AS R10", "ROUND(V, -1) AS 1R", "ROUND(V, -2) AS 2R" ]
+        },
+        "formats" : {
+          "keyFormat" : {
+            "format" : "KAFKA"
+          },
+          "valueFormat" : {
+            "format" : "DELIMITED"
+          }
+        },
+        "topicName" : "OUTPUT"
+      },
+      "queryId" : "CSAS_OUTPUT_0"
+    }
+  } ],
+  "configs" : {
+    "ksql.extension.dir" : "ext",
+    "ksql.streams.cache.max.bytes.buffering" : "0",
+    "ksql.security.extension.class" : null,
+    "metric.reporters" : "",
+    "ksql.transient.prefix" : "transient_",
+    "ksql.query.status.running.threshold.seconds" : "300",
+    "ksql.streams.default.deserialization.exception.handler" : "io.confluent.ksql.errors.LogMetricAndContinueExceptionHandler",
+    "ksql.output.topic.name.prefix" : "",
+    "ksql.query.pull.enable.standby.reads" : "false",
+    "ksql.streams.max.task.idle.ms" : "0",
+    "ksql.query.error.max.queue.size" : "10",
+    "ksql.internal.topic.min.insync.replicas" : "1",
+    "ksql.streams.shutdown.timeout.ms" : "300000",
+    "ksql.internal.topic.replicas" : "1",
+    "ksql.insert.into.values.enabled" : "true",
+    "ksql.query.pull.max.allowed.offset.lag" : "9223372036854775807",
+    "ksql.query.pull.max.qps" : "2147483647",
+    "ksql.access.validator.enable" : "auto",
+    "ksql.streams.bootstrap.servers" : "localhost:0",
+    "ksql.query.pull.metrics.enabled" : "false",
+    "ksql.create.or.replace.enabled" : "true",
+    "ksql.metrics.extension" : null,
+    "ksql.hidden.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.cast.strings.preserve.nulls" : "true",
+    "ksql.authorization.cache.max.entries" : "10000",
+    "ksql.pull.queries.enable" : "true",
+    "ksql.suppress.enabled" : "false",
+    "ksql.sink.window.change.log.additional.retention" : "1000000",
+    "ksql.readonly.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.query.persistent.active.limit" : "2147483647",
+    "ksql.persistence.wrap.single.values" : null,
+    "ksql.authorization.cache.expiry.time.secs" : "30",
+    "ksql.query.retry.backoff.initial.ms" : "15000",
+    "ksql.schema.registry.url" : "",
+    "ksql.properties.overrides.denylist" : "",
+    "ksql.streams.auto.offset.reset" : "earliest",
+    "ksql.connect.url" : "http://localhost:8083",
+    "ksql.service.id" : "some.ksql.service.id",
+    "ksql.streams.default.production.exception.handler" : "io.confluent.ksql.errors.ProductionExceptionHandlerUtil$LogAndFailProductionExceptionHandler",
+    "ksql.enable.metastore.backup" : "false",
+    "ksql.streams.commit.interval.ms" : "2000",
+    "ksql.streams.auto.commit.interval.ms" : "0",
+    "ksql.streams.topology.optimization" : "all",
+    "ksql.query.retry.backoff.max.ms" : "900000",
+    "ksql.streams.num.stream.threads" : "4",
+    "ksql.timestamp.throw.on.invalid" : "false",
+    "ksql.metrics.tags.custom" : "",
+    "ksql.udfs.enabled" : "true",
+    "ksql.udf.enable.security.manager" : "true",
+    "ksql.connect.worker.config" : "",
+    "ksql.udf.collect.metrics" : "false",
+    "ksql.persistent.prefix" : "query_",
+    "ksql.metastore.backup.location" : "",
+    "ksql.error.classifier.regex" : "",
+    "ksql.suppress.buffer.size.bytes" : "-1"
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/spec.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/spec.json
new file mode 100644
index 000000000000..9512ebb3b68d
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/spec.json
@@ -0,0 +1,82 @@
+{
+  "version" : "6.1.0",
+  "timestamp" : 1600280487241,
+  "path" : "query-validation-tests/math.json",
+  "schemas" : {
+    "CSAS_OUTPUT_0.KsqlTopic.Source" : {
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    },
+    "CSAS_OUTPUT_0.OUTPUT" : {
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16), `R1` DECIMAL(33, 16), `R2` DECIMAL(33, 16), `R10` DECIMAL(33, 16), `1R` DECIMAL(33, 16), `2R` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    }
+  },
+  "testCase" : {
+    "name" : "round with large DECIMAL values - DELIMITED",
+    "inputs" : [ {
+      "topic" : "test_topic",
+      "key" : null,
+      "value" : "12345678987654321.2345678987654321"
+    } ],
+    "outputs" : [ {
+      "topic" : "OUTPUT",
+      "key" : null,
+      "value" : "\"12,345,678,987,654,321\",\"12,345,678,987,654,321.0000000000000000\",\"12,345,678,987,654,321.2000000000000000\",\"12,345,678,987,654,321.2300000000000000\",\"12,345,678,987,654,321.2345678988000000\",\"12,345,678,987,654,320.0000000000000000\",\"12,345,678,987,654,300.0000000000000000\""
+    } ],
+    "topics" : [ {
+      "name" : "OUTPUT",
+      "replicas" : 1,
+      "numPartitions" : 4
+    }, {
+      "name" : "test_topic",
+      "replicas" : 1,
+      "numPartitions" : 4
+    } ],
+    "statements" : [ "CREATE STREAM test (ID STRING KEY, v DECIMAL(33, 16)) WITH (kafka_topic='test_topic', value_format='DELIMITED');", "CREATE STREAM OUTPUT AS SELECT ID, ROUND(v) as R0, ROUND(v, 0) as R00, ROUND(v, 1) as R1, ROUND(v, 2) as R2, ROUND(v, 10) as R10, ROUND(v , -1) as 1R , ROUND(v , -2) as 2R  FROM test;" ],
+    "post" : {
+      "sources" : [ {
+        "name" : "OUTPUT",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16), `R1` DECIMAL(33, 16), `R2` DECIMAL(33, 16), `R10` DECIMAL(33, 16), `1R` DECIMAL(33, 16), `2R` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      }, {
+        "name" : "TEST",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      } ],
+      "topics" : {
+        "topics" : [ {
+          "name" : "test_topic",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "DELIMITED"
+          },
+          "partitions" : 4
+        }, {
+          "name" : "OUTPUT",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "DELIMITED"
+          },
+          "partitions" : 4
+        } ]
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/topology b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/topology
new file mode 100644
index 000000000000..441a8f282644
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_DELIMITED/6.1.0_1600280487241/topology
@@ -0,0 +1,13 @@
+Topologies:
+   Sub-topology: 0
+    Source: KSTREAM-SOURCE-0000000000 (topics: [test_topic])
+      --> KSTREAM-TRANSFORMVALUES-0000000001
+    Processor: KSTREAM-TRANSFORMVALUES-0000000001 (stores: [])
+      --> Project
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: Project (stores: [])
+      --> KSTREAM-SINK-0000000003
+      <-- KSTREAM-TRANSFORMVALUES-0000000001
+    Sink: KSTREAM-SINK-0000000003 (topic: OUTPUT)
+      <-- Project
+
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/plan.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/plan.json
new file mode 100644
index 000000000000..3ad84a2318aa
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/plan.json
@@ -0,0 +1,140 @@
+{
+  "plan" : [ {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM TEST (ID STRING KEY, V DECIMAL(33, 16)) WITH (KAFKA_TOPIC='test_topic', VALUE_FORMAT='JSON');",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "TEST",
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "topicName" : "test_topic",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "JSON"
+        }
+      },
+      "orReplace" : false
+    }
+  }, {
+    "@type" : "ksqlPlanV1",
+    "statementText" : "CREATE STREAM OUTPUT AS SELECT\n  TEST.ID ID,\n  ROUND(TEST.V) R0,\n  ROUND(TEST.V, 0) R00\nFROM TEST TEST\nEMIT CHANGES",
+    "ddlCommand" : {
+      "@type" : "createStreamV1",
+      "sourceName" : "OUTPUT",
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+      "topicName" : "OUTPUT",
+      "formats" : {
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "valueFormat" : {
+          "format" : "JSON"
+        }
+      },
+      "orReplace" : false
+    },
+    "queryPlan" : {
+      "sources" : [ "TEST" ],
+      "sink" : "OUTPUT",
+      "physicalPlan" : {
+        "@type" : "streamSinkV1",
+        "properties" : {
+          "queryContext" : "OUTPUT"
+        },
+        "source" : {
+          "@type" : "streamSelectV1",
+          "properties" : {
+            "queryContext" : "Project"
+          },
+          "source" : {
+            "@type" : "streamSourceV1",
+            "properties" : {
+              "queryContext" : "KsqlTopic/Source"
+            },
+            "topicName" : "test_topic",
+            "formats" : {
+              "keyFormat" : {
+                "format" : "KAFKA"
+              },
+              "valueFormat" : {
+                "format" : "JSON"
+              }
+            },
+            "sourceSchema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)"
+          },
+          "keyColumnNames" : [ "ID" ],
+          "selectExpressions" : [ "ROUND(V) AS R0", "ROUND(V, 0) AS R00" ]
+        },
+        "formats" : {
+          "keyFormat" : {
+            "format" : "KAFKA"
+          },
+          "valueFormat" : {
+            "format" : "JSON"
+          }
+        },
+        "topicName" : "OUTPUT"
+      },
+      "queryId" : "CSAS_OUTPUT_0"
+    }
+  } ],
+  "configs" : {
+    "ksql.extension.dir" : "ext",
+    "ksql.streams.cache.max.bytes.buffering" : "0",
+    "ksql.security.extension.class" : null,
+    "metric.reporters" : "",
+    "ksql.transient.prefix" : "transient_",
+    "ksql.query.status.running.threshold.seconds" : "300",
+    "ksql.streams.default.deserialization.exception.handler" : "io.confluent.ksql.errors.LogMetricAndContinueExceptionHandler",
+    "ksql.output.topic.name.prefix" : "",
+    "ksql.query.pull.enable.standby.reads" : "false",
+    "ksql.streams.max.task.idle.ms" : "0",
+    "ksql.query.error.max.queue.size" : "10",
+    "ksql.internal.topic.min.insync.replicas" : "1",
+    "ksql.streams.shutdown.timeout.ms" : "300000",
+    "ksql.internal.topic.replicas" : "1",
+    "ksql.insert.into.values.enabled" : "true",
+    "ksql.query.pull.max.allowed.offset.lag" : "9223372036854775807",
+    "ksql.query.pull.max.qps" : "2147483647",
+    "ksql.access.validator.enable" : "auto",
+    "ksql.streams.bootstrap.servers" : "localhost:0",
+    "ksql.query.pull.metrics.enabled" : "false",
+    "ksql.create.or.replace.enabled" : "true",
+    "ksql.metrics.extension" : null,
+    "ksql.hidden.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.cast.strings.preserve.nulls" : "true",
+    "ksql.authorization.cache.max.entries" : "10000",
+    "ksql.pull.queries.enable" : "true",
+    "ksql.suppress.enabled" : "false",
+    "ksql.sink.window.change.log.additional.retention" : "1000000",
+    "ksql.readonly.topics" : "_confluent.*,__confluent.*,_schemas,__consumer_offsets,__transaction_state,connect-configs,connect-offsets,connect-status,connect-statuses",
+    "ksql.query.persistent.active.limit" : "2147483647",
+    "ksql.persistence.wrap.single.values" : null,
+    "ksql.authorization.cache.expiry.time.secs" : "30",
+    "ksql.query.retry.backoff.initial.ms" : "15000",
+    "ksql.schema.registry.url" : "",
+    "ksql.properties.overrides.denylist" : "",
+    "ksql.streams.auto.offset.reset" : "earliest",
+    "ksql.connect.url" : "http://localhost:8083",
+    "ksql.service.id" : "some.ksql.service.id",
+    "ksql.streams.default.production.exception.handler" : "io.confluent.ksql.errors.ProductionExceptionHandlerUtil$LogAndFailProductionExceptionHandler",
+    "ksql.enable.metastore.backup" : "false",
+    "ksql.streams.commit.interval.ms" : "2000",
+    "ksql.streams.auto.commit.interval.ms" : "0",
+    "ksql.streams.topology.optimization" : "all",
+    "ksql.query.retry.backoff.max.ms" : "900000",
+    "ksql.streams.num.stream.threads" : "4",
+    "ksql.timestamp.throw.on.invalid" : "false",
+    "ksql.metrics.tags.custom" : "",
+    "ksql.udfs.enabled" : "true",
+    "ksql.udf.enable.security.manager" : "true",
+    "ksql.connect.worker.config" : "",
+    "ksql.udf.collect.metrics" : "false",
+    "ksql.persistent.prefix" : "query_",
+    "ksql.metastore.backup.location" : "",
+    "ksql.error.classifier.regex" : "",
+    "ksql.suppress.buffer.size.bytes" : "-1"
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/spec.json b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/spec.json
new file mode 100644
index 000000000000..67726d967a5d
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/spec.json
@@ -0,0 +1,87 @@
+{
+  "version" : "6.1.0",
+  "timestamp" : 1600280487303,
+  "path" : "query-validation-tests/math.json",
+  "schemas" : {
+    "CSAS_OUTPUT_0.KsqlTopic.Source" : {
+      "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    },
+    "CSAS_OUTPUT_0.OUTPUT" : {
+      "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+      "serdeOptions" : [ ]
+    }
+  },
+  "testCase" : {
+    "name" : "round with large DECIMAL values - JSON",
+    "inputs" : [ {
+      "topic" : "test_topic",
+      "key" : null,
+      "value" : {
+        "v" : 12345678987654321.2345678987654321
+      }
+    } ],
+    "outputs" : [ {
+      "topic" : "OUTPUT",
+      "key" : null,
+      "value" : {
+        "R0" : 12345678987654321,
+        "R00" : 12345678987654321.0000000000000000
+      }
+    } ],
+    "topics" : [ {
+      "name" : "OUTPUT",
+      "replicas" : 1,
+      "numPartitions" : 4
+    }, {
+      "name" : "test_topic",
+      "replicas" : 1,
+      "numPartitions" : 4
+    } ],
+    "statements" : [ "CREATE STREAM test (ID STRING KEY, v DECIMAL(33, 16)) WITH (kafka_topic='test_topic', value_format='JSON');", "CREATE STREAM OUTPUT AS SELECT ID, ROUND(v) as R0, ROUND(v, 0) as R00 FROM test;" ],
+    "post" : {
+      "sources" : [ {
+        "name" : "OUTPUT",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `R0` DECIMAL(17, 0), `R00` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      }, {
+        "name" : "TEST",
+        "type" : "STREAM",
+        "schema" : "`ID` STRING KEY, `V` DECIMAL(33, 16)",
+        "keyFormat" : {
+          "format" : "KAFKA"
+        },
+        "serdeOptions" : [ ]
+      } ],
+      "topics" : {
+        "topics" : [ {
+          "name" : "test_topic",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "JSON"
+          },
+          "partitions" : 4
+        }, {
+          "name" : "OUTPUT",
+          "keyFormat" : {
+            "formatInfo" : {
+              "format" : "KAFKA"
+            }
+          },
+          "valueFormat" : {
+            "format" : "JSON"
+          },
+          "partitions" : 4
+        } ]
+      }
+    }
+  }
+}
\ No newline at end of file
diff --git a/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/topology b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/topology
new file mode 100644
index 000000000000..441a8f282644
--- /dev/null
+++ b/ksqldb-functional-tests/src/test/resources/historical_plans/math_-_round_with_large_DECIMAL_values_-_JSON/6.1.0_1600280487303/topology
@@ -0,0 +1,13 @@
+Topologies:
+   Sub-topology: 0
+    Source: KSTREAM-SOURCE-0000000000 (topics: [test_topic])
+      --> KSTREAM-TRANSFORMVALUES-0000000001
+    Processor: KSTREAM-TRANSFORMVALUES-0000000001 (stores: [])
+      --> Project
+      <-- KSTREAM-SOURCE-0000000000
+    Processor: Project (stores: [])
+      --> KSTREAM-SINK-0000000003
+      <-- KSTREAM-TRANSFORMVALUES-0000000001
+    Sink: KSTREAM-SINK-0000000003 (topic: OUTPUT)
+      <-- Project
+
diff --git a/ksqldb-functional-tests/src/test/resources/query-validation-tests/math.json b/ksqldb-functional-tests/src/test/resources/query-validation-tests/math.json
index 46bd68de1809..2d44cf6a4ac3 100644
--- a/ksqldb-functional-tests/src/test/resources/query-validation-tests/math.json
+++ b/ksqldb-functional-tests/src/test/resources/query-validation-tests/math.json
@@ -210,7 +210,7 @@
       ]
     },
     {
-      "name": "round with large DECIMAL values",
+      "name": "round with large DECIMAL values - DELIMITED",
       "statements": [
         "CREATE STREAM test (ID STRING KEY, v DECIMAL(33, 16)) WITH (kafka_topic='test_topic', value_format='DELIMITED');",
         "CREATE STREAM OUTPUT AS SELECT ID, ROUND(v) as R0, ROUND(v, 0) as R00, ROUND(v, 1) as R1, ROUND(v, 2) as R2, ROUND(v, 10) as R10, ROUND(v , -1) as 1R , ROUND(v , -2) as 2R  FROM test;"
@@ -233,6 +233,29 @@
           }
         ]
       }
+    },
+    {
+      "name": "round with large DECIMAL values",
+      "format": ["AVRO", "JSON"],
+      "statements": [
+        "CREATE STREAM test (ID STRING KEY, v DECIMAL(33, 16)) WITH (kafka_topic='test_topic', value_format='{FORMAT}');",
+        "CREATE STREAM OUTPUT AS SELECT ID, ROUND(v) as R0, ROUND(v, 0) as R00 FROM test;"
+      ],
+      "inputs": [
+        {"topic": "test_topic", "value": {"v": 12345678987654321.2345678987654321}}
+      ],
+      "outputs": [
+        {"topic": "OUTPUT", "value": {"R0": 12345678987654321, "R00": 12345678987654321.0000000000000000}}
+      ],
+      "post": {
+        "sources": [
+          {
+            "name": "OUTPUT",
+            "type": "stream",
+            "schema": "ID STRING KEY, R0 DECIMAL(17,0), R00 DECIMAL(33,16)"
+          }
+        ]
+      }
     }
   ]
 }
\ No newline at end of file