diff --git a/algorithm-exercises-java/src/test/java/ae/Problem0000Test.java b/algorithm-exercises-java/src/test/java/ae/Problem0000Test.java
index 2c05b2e..df2d2eb 100644
--- a/algorithm-exercises-java/src/test/java/ae/Problem0000Test.java
+++ b/algorithm-exercises-java/src/test/java/ae/Problem0000Test.java
@@ -10,7 +10,6 @@ class Problem0000Test {
   @Test void problem0000() {
 
     Integer answer = null;
-    // Integer input = 0;
     Integer solutionFound = Problem0000.problem0000();
 
     assertEquals(answer, solutionFound,
diff --git a/algorithm-exercises-java/src/test/java/ae/projecteuler/Problem0023Test.java b/algorithm-exercises-java/src/test/java/ae/projecteuler/Problem0023Test.java
index 779cdac..538eb26 100644
--- a/algorithm-exercises-java/src/test/java/ae/projecteuler/Problem0023Test.java
+++ b/algorithm-exercises-java/src/test/java/ae/projecteuler/Problem0023Test.java
@@ -22,7 +22,7 @@ void problem0023smallCase1(
 
     Integer solutionFound = Problem0023.problem0023(inputUnderLimit, inputSuperLimit);
 
-    String log = String.format("Problem 0023 {0} answer must be: {1}", testCase, answer);
+    String log = String.format("Problem 0023 %s answer must be: %d", testCase, answer);
     assertEquals(answer, solutionFound, log);
   }
 
diff --git a/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/BigNumTest.java b/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/BigNumTest.java
index 0090ef2..381e4d9 100644
--- a/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/BigNumTest.java
+++ b/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/BigNumTest.java
@@ -71,8 +71,13 @@ class BigNumTest {
         solutionFound.toArray()
     );
 
-    solutionFound = solutionFound.bigSum(new BigNum(6));
+    BigNum solutionFoundB = new BigNum(input);
+    solutionFoundB.bigSum(solutionFound);
 
+    assertArrayEquals(
+        expectedAnswer,
+        solutionFoundB.toArray()
+    );
   }
 
   @Test void bigMultiplyRowToBigNumTest() {
@@ -102,8 +107,6 @@ class BigNumTest {
         new Integer[]{ 8, 9, 9, 1 },
         BigNum.bigMultiplyRowToBigNum("999", 9).toArray()
     );
-    solutionFound = solutionFound.bigSum(new BigNum(6));
-
   }
 
   @Test void bigMultiplyTest() {
diff --git a/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/PalindromeTest.java b/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/PalindromeTest.java
index 2c27c25..5763ce9 100644
--- a/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/PalindromeTest.java
+++ b/algorithm-exercises-java/src/test/java/ae/projecteuler/helper/PalindromeTest.java
@@ -17,16 +17,6 @@ private class PalindromTestCase {
     }
   }
 
-  // @Test void instanceCaseTest() {
-  //   Palindrome classUnderTest = new Palindrome();
-
-  //   assertNotNull(classUnderTest);
-  //   assertInstanceOf(
-  //       Palindrome.class,
-  //       classUnderTest,
-  //       String.format("Must be an instance of %s", Palindrome.class));
-  // }
-
   @Test void listOfPalindromBorderCaseTest() {
 
     PalindromTestCase[] testCases = {
@@ -37,6 +27,4 @@ private class PalindromTestCase {
       assertEquals(testCase.answer, Palindrome.isPalindrome(testCase.input));
     }
   }
-
-
 }