diff --git a/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/FunctionTestSuite.java b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/FunctionTestSuite.java
index 42bd7bbcbc..c7f4050b18 100644
--- a/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/FunctionTestSuite.java
+++ b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/FunctionTestSuite.java
@@ -1,11 +1,11 @@
-package com.baeldung;
-
-import org.junit.runner.RunWith;
-import org.junit.runners.Suite;
-import org.junit.runners.Suite.SuiteClasses;
-
-@RunWith(Suite.class)
-@SuiteClasses({StringFunctionTest.class, MathFunctionTest.class})
-public class FunctionTestSuite {
-
-}
+package com.baeldung;
+
+import org.junit.runner.RunWith;
+import org.junit.runners.Suite;
+import org.junit.runners.Suite.SuiteClasses;
+
+@RunWith(Suite.class)
+@SuiteClasses({StringFunctionTest.class, MathFunctionTest.class})
+public class FunctionTestSuite {
+
+}
diff --git a/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/MathFunctionTest.java b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/MathFunctionTest.java
new file mode 100644
index 0000000000..9a609c3e93
--- /dev/null
+++ b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/MathFunctionTest.java
@@ -0,0 +1,29 @@
+package com.baeldung;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class MathFunctionTest {
+
+    @Test
+    public void test_addingIntegers_returnsSum() throws InterruptedException {
+        assertEquals(22, Math.addExact(10, 12));
+
+    }
+
+    @Test
+    public void test_multiplyingIntegers_returnsProduct() {
+        assertEquals(120, Math.multiplyExact(10, 12));
+    }
+
+    @Test
+    public void test_subtractingIntegers_returnsDifference() {
+        assertEquals(2, Math.subtractExact(12, 10));
+    }
+
+    @Test
+    public void test_minimumInteger() {
+        assertEquals(10, Math.min(10, 12));
+    }
+}
diff --git a/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/StringFunctionTest.java b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/StringFunctionTest.java
new file mode 100644
index 0000000000..9adfea8ff0
--- /dev/null
+++ b/testing-modules/parallel-tests-junit/src/test/java/com/baeldung/StringFunctionTest.java
@@ -0,0 +1,18 @@
+package com.baeldung;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+public class StringFunctionTest {
+
+    @Test
+    public void test_upperCase() {
+        assertEquals("TESTCASE", "testCase".toUpperCase());
+    }
+
+    @Test
+    public void test_indexOf() {
+        assertEquals(1, "testCase".indexOf("e"));
+    }
+}