diff --git a/src/main/java/LoopFun.java b/src/main/java/LoopFun.java
index 801ab56..8fbed37 100644
--- a/src/main/java/LoopFun.java
+++ b/src/main/java/LoopFun.java
@@ -1,4 +1,4 @@
- 
+
 
 public class LoopFun
 {
@@ -10,7 +10,12 @@ public class LoopFun
        * @return the factorial of the number
        */
       public Integer factorial(Integer number){
-          return null;
+          int fact = 1;
+          for (int index=number; index >0; index--) {
+//              System.out.println(index);
+              fact = index*fact;
+          }
+          return fact;
       }
 
       /**
@@ -21,7 +26,15 @@ public Integer factorial(Integer number){
        * @return Upper case string of the first letter of each word
        */
       public String acronym(String phrase) {
-          return null;
+          char[] phraseChars = phrase.toCharArray();
+          String acronym = "";
+          for (int index = 0; index < phraseChars.length; index++) {
+              if (phraseChars[index] != ' ' && (index == 0 || phraseChars[index - 1] == ' ')) {
+                  acronym+=phraseChars[index];
+              }
+          }
+//          System.out.println(acronym);
+          return acronym.toUpperCase();
       }
 
       /**
@@ -37,6 +50,13 @@ public String acronym(String phrase) {
        * @return the encrypted string by shifting each character by three character
        */
       public String encrypt(String word) {
-          return null;
+          char[] shiftChar = word.toCharArray();
+          for (int in = 0; in < shiftChar.length; in++) {
+              if (Character.isLetter(shiftChar[in])) {
+                  shiftChar[in] = (char) ((shiftChar[in] + 3 - (int)'a') % 26 + (int)'a');
+              }
+          }
+          word = String.valueOf(shiftChar);
+          return word;//          String og = "";
       }
 }
diff --git a/src/main/java/MathUtilities.java b/src/main/java/MathUtilities.java
index e067c75..a677c0e 100644
--- a/src/main/java/MathUtilities.java
+++ b/src/main/java/MathUtilities.java
@@ -9,7 +9,7 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public Integer add(Integer baseValue, Integer valueToAdd){
-      return null;
+      return baseValue+valueToAdd;
   }
 
   /**
@@ -19,7 +19,7 @@ public Integer add(Integer baseValue, Integer valueToAdd){
    * @return the sum of the two numbers
    */
   public Double add(Double baseValue, Double valueToAdd){
-      return null;
+      return baseValue+valueToAdd;
   }
 
   /**
@@ -28,7 +28,7 @@ public Double add(Double baseValue, Double valueToAdd){
    * @return the half of the number in double
    */
   public Double half(Integer number) {
-      return null;
+      return number/2.0;
   }
 
   /**
@@ -37,7 +37,11 @@ public Double half(Integer number) {
    * @return true if the number is odd, false if it is even
    */
   public Boolean isOdd(Integer number){
-      return null;
+      boolean isOdd = false;
+      if ((number%2 != 0)) {
+          isOdd = true;
+      }
+      return isOdd;
   }
 
 
@@ -47,7 +51,7 @@ public Boolean isOdd(Integer number){
    * @return the result of the number multiply by itself
    */
   public Integer square(Integer number) {
-      return null;
+      return number*number;
   }
 
 }
diff --git a/src/main/java/StringUtilities.java b/src/main/java/StringUtilities.java
index e3ea8a9..5f02bf0 100644
--- a/src/main/java/StringUtilities.java
+++ b/src/main/java/StringUtilities.java
@@ -5,7 +5,7 @@ public class StringUtilities {
      * @return `input`
      */
     public String returnInput(String input) {
-        return null;
+        return input;
     }
 
     /**
@@ -14,7 +14,7 @@ public String returnInput(String input) {
      * @return the concatenation of `baseValue` and `valueToBeAdded`
      */
     public String concatenate(String baseValue, String valueToBeAdded) {
-        return null;
+        return baseValue.concat(valueToBeAdded);
     }
 
     /**
@@ -22,7 +22,11 @@ public String concatenate(String baseValue, String valueToBeAdded) {
      * @return identical string with characters in opposite order
      */
     public String reverse(String valueToBeReversed) {
-        return null;
+        String revString = "";
+        for (int in = valueToBeReversed.length()-1; in>=0; in--) {
+            revString += valueToBeReversed.charAt(in);
+        }
+        return revString;
     }
 
     /**
@@ -30,7 +34,8 @@ public String reverse(String valueToBeReversed) {
      * @return middle character of `word`
      */
     public Character getMiddleCharacter(String word) {
-        return null;
+        int len = word.length();
+        return word.charAt(len/2);
     }
 
     /**
@@ -39,7 +44,8 @@ public Character getMiddleCharacter(String word) {
      * @return `value` with char of value `charToRemove` removed
      */
     public String removeCharacter(String value, Character charToRemove) {
-        return null;
+        String res = value.replaceAll("(?i)" + charToRemove, "");
+        return res;
     }
 
     /**
@@ -47,6 +53,7 @@ public String removeCharacter(String value, Character charToRemove) {
      * @return last `word` in sentence
      */
     public String getLastWord(String sentence) {
-        return null;
+        String[] words = sentence.split(" ");
+        return words[words.length - 1];
     }
 }
diff --git a/src/test/java/LoopsFunAcronymTest.java b/src/test/java/LoopsFunAcronymTest.java
index 61e2f5b..8ef11cb 100644
--- a/src/test/java/LoopsFunAcronymTest.java
+++ b/src/test/java/LoopsFunAcronymTest.java
@@ -51,6 +51,7 @@ public void test3() {
         assertEquals(expected, actual);
     }
 
+    @Test
     public void test6() {
         // given
         String phrase = "Center Disease Control Whistle Blower";
@@ -63,6 +64,7 @@ public void test6() {
         assertEquals(expected, actual);
     }
 
+    @Test
     public void test7() {
         // given
         String phrase = "Tuskegee Macon County, Alabama";
@@ -75,6 +77,7 @@ public void test7() {
         assertEquals(expected, actual);
     }
 
+    @Test
     public void test8() {
         // given
         String phrase = "John Charles Cutler";
@@ -100,6 +103,7 @@ public void test9() {
         assertEquals(expected, actual);
     }
 
+    @Test
     public void test4() {
         // given
         String phrase = "Tactical Reconnaissance Nuclear Powered Aerospace Platform";