diff --git a/java-numbers/src/main/java/com/baeldung/formatNumber/FormatNumber.java b/java-numbers/src/main/java/com/baeldung/formatNumber/FormatNumber.java
index a9925dee9d..a0a9e05e83 100644
--- a/java-numbers/src/main/java/com/baeldung/formatNumber/FormatNumber.java
+++ b/java-numbers/src/main/java/com/baeldung/formatNumber/FormatNumber.java
@@ -7,30 +7,6 @@ import java.text.NumberFormat;
 import java.util.Locale;
 
 public class FormatNumber {
-        private static final double D = 4.2352989244d;
-        private static final double F = 8.6994540927d;
-
-        public static void main(String[] args) {
-                System.out.println(D + " with Big Decimal (2 places) is " + withBigDecimal(D, 2));
-                System.out.println(D + " with Big Decimal (3 places) is " + withBigDecimal(D, 3));
-                System.out.println(F + " with Big Decimal (2 places) is " + withBigDecimal(F, 2));
-                System.out.println(F + " with Big Decimal (3 places) is " + withBigDecimal(F, 3));
-                System.out.println(D + " with Math.round is (2 places) " + withMathRound(D, 2));
-                System.out.println(D + " with Math.round is (3 places) " + withMathRound(D, 3));
-                System.out.println(F + " with Math.round is (2 places) " + withMathRound(F, 2));
-                System.out.println(F + " with Math.round is (3 places) " + withMathRound(F, 3));
-                System.out.println(D + " with String Format is (2 places) " + withStringFormat(D, 2));
-                System.out.println(D + " with String Format is (3 places) " + withStringFormat(D, 3));
-                System.out.println(F + " with String Format is (2 places) " + withStringFormat(F, 2));
-                System.out.println(F + " with String Format is (3 places) " + withStringFormat(F, 3));
-                System.out.println(D + " with Decimal Format (local) is " + withDecimalFormatLocal(D));
-                System.out.println(D + " with Decimal Format (2 places) is " + withDecimalFormatPattern(D, 2));
-                System.out.println(D + " with Decimal Format (3 places) is " + withDecimalFormatPattern(D, 3));
-                System.out.println(F + " with Decimal Format is (local) " + withDecimalFormatLocal(F));
-                System.out.println(F + " with Decimal Format is (2 places) " + withDecimalFormatPattern(F, 2));
-                System.out.println(F + " with Decimal Format is (3 places) " + withDecimalFormatPattern(F, 3));
-        }
-
         public static double withBigDecimal(double value, int places) {
                 if (places < 0)
                         throw new IllegalArgumentException();
diff --git a/java-numbers/src/test/java/com/baeldung/formatNumber/FormatNumberTest.java b/java-numbers/src/test/java/com/baeldung/formatNumber/FormatNumberTest.java
index 1e402e4dc9..cb4e7631f7 100644
--- a/java-numbers/src/test/java/com/baeldung/formatNumber/FormatNumberTest.java
+++ b/java-numbers/src/test/java/com/baeldung/formatNumber/FormatNumberTest.java
@@ -1,42 +1,37 @@
 package com.baeldung.formatNumber;
 
-import org.apache.commons.math3.util.Precision;
-import org.decimal4j.util.DoubleRounder;
-import org.junit.Assert;
 import org.junit.Test;
 
+import static com.baeldung.formatNumber.FormatNumber.*;
+import static org.assertj.core.api.Assertions.*;
+
 public class FormatNumberTest {
-        private double value = 2.03456d;
-        private int places = 2;
-        private double expected = 2.03d;
+        private static final double D = 4.2352989244d;
+        private static final double F = 8.6994540927d;
 
         @Test public void givenDecimalNumber_whenFormatNumberToNDecimalPlaces_thenGetExpectedResult() {
-                double delta = 0.0d;
-                Assert.assertEquals(expected, FormatNumber.withBigDecimal(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withDecimalFormatPattern(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withMathRound(value, places), delta);
 
-                places = 3;
-                expected = 2.035d;
+                assertThat(withBigDecimal(D, 2)).isEqualTo(4.24);
+                assertThat(withBigDecimal(D, 3)).isEqualTo(4.235);
+                assertThat(withBigDecimal(F, 2)).isEqualTo(8.7);
+                assertThat(withBigDecimal(F, 3)).isEqualTo(8.699);
 
-                Assert.assertEquals(expected, FormatNumber.withBigDecimal(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withDecimalFormatPattern(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withMathRound(value, places), delta);
+                assertThat(withMathRound(D, 2)).isEqualTo(4.24);
+                assertThat(withMathRound(D, 3)).isEqualTo(4.235);
+                assertThat(withMathRound(F, 2)).isEqualTo(8.7);
+                assertThat(withMathRound(F, 3)).isEqualTo(8.699);
 
-                value = 256.024d;
-                places = 2;
-                expected = 256.02d;
+                assertThat(withStringFormat(D, 2)).isEqualTo("4.24");
+                assertThat(withStringFormat(D, 3)).isEqualTo("4.235");
+                assertThat(withStringFormat(F, 2)).isEqualTo("8.70");
+                assertThat(withStringFormat(F, 3)).isEqualTo("8.699");
 
-                Assert.assertEquals(expected, FormatNumber.withBigDecimal(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withDecimalFormatPattern(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withMathRound(value, places), delta);
+                assertThat(withDecimalFormatLocal(D)).isEqualTo(4.235);
+                assertThat(withDecimalFormatLocal(F)).isEqualTo(8.699);
 
-                value = 260.773d;
-                places = 2;
-                expected = 260.77d;
-
-                Assert.assertEquals(expected, FormatNumber.withBigDecimal(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withDecimalFormatPattern(value, places), delta);
-                Assert.assertEquals(expected, FormatNumber.withMathRound(value, places), delta);
+                assertThat(withDecimalFormatPattern(D, 2)).isEqualTo(4.24);
+                assertThat(withDecimalFormatPattern(D, 3)).isEqualTo(4.235);
+                assertThat(withDecimalFormatPattern(F, 2)).isEqualTo(8.7);
+                assertThat(withDecimalFormatPattern(F, 3)).isEqualTo(8.699);
         }
 }