diff --git a/src/main/java/LoopFun.java b/src/main/java/LoopFun.java
index 801ab56..de67694 100644
--- a/src/main/java/LoopFun.java
+++ b/src/main/java/LoopFun.java
@@ -1,4 +1,4 @@
- 
+import java.util.ArrayList;
 
 public class LoopFun
 {
@@ -10,7 +10,9 @@ public class LoopFun
        * @return the factorial of the number
        */
       public Integer factorial(Integer number){
-          return null;
+          int fact = 1;
+          for (int i = 1; i  <= number; i++) {fact = fact * i;}
+          return fact;
       }
 
       /**
@@ -21,7 +23,30 @@ public Integer factorial(Integer number){
        * @return Upper case string of the first letter of each word
        */
       public String acronym(String phrase) {
-          return null;
+            
+          String[] words = phrase.split("\\W+");
+          String output = "";
+          for (int i = 0; i <words.length; i++) {
+              // System.out.println(words[i]); // tests if words are being split
+              output += words[i].charAt(0);
+
+          }
+
+          return output.toUpperCase();
+          /*
+          char c = phrase.charAt(0);
+          String output = phrase;
+          String OutPut = null;
+          for (int i = 1; i < phrase.length(); i++) {
+              if (Character.isWhitespace(phrase.charAt(i))) {
+                  output = output + phrase.charAt(i);
+                  output += phrase.charAt(i+1);
+              }
+              OutPut = output.replaceAll("\\s+","").toUpperCase();
+          }
+
+        return OutPut;
+        */
       }
 
       /**
@@ -37,6 +62,17 @@ public String acronym(String phrase) {
        * @return the encrypted string by shifting each character by three character
        */
       public String encrypt(String word) {
-          return null;
+          char[] pass = word.toCharArray();
+          int shiftVal = 3;
+          for (int i = 0; i < word.length(); i++) {
+              if (pass[i] >= 120) {
+                  pass[i] -= 23;
+
+              } else {
+                  pass[i] += shiftVal;
+              }
+          }
+          String password = new String(pass);
+          return password;
       }
 }
diff --git a/src/main/java/MathUtilities.java b/src/main/java/MathUtilities.java
index e067c75..8949b02 100644
--- a/src/main/java/MathUtilities.java
+++ b/src/main/java/MathUtilities.java
@@ -1,4 +1,4 @@
- 
+ import java.lang.Math;
 
 public class MathUtilities{
     
@@ -9,7 +9,8 @@ public class MathUtilities{
    * @return the sum of the two numbers
    */
   public Integer add(Integer baseValue, Integer valueToAdd){
-      return null;
+
+      return baseValue + valueToAdd;
   }
 
   /**
@@ -19,7 +20,8 @@ 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 +30,8 @@ public Double add(Double baseValue, Double valueToAdd){
    * @return the half of the number in double
    */
   public Double half(Integer number) {
-      return null;
+
+      return (double) number /2 ;
   }
 
   /**
@@ -37,7 +40,12 @@ public Double half(Integer number) {
    * @return true if the number is odd, false if it is even
    */
   public Boolean isOdd(Integer number){
-      return null;
+      if (number %2 != 0 ) {
+          return true;
+      } else {
+          return false;
+      }
+
   }
 
 
@@ -47,7 +55,7 @@ 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..5add6e8 100644
--- a/src/main/java/StringUtilities.java
+++ b/src/main/java/StringUtilities.java
@@ -1,3 +1,4 @@
+import java.lang.StringBuilder;
 
 public class StringUtilities {
     /**
@@ -5,7 +6,8 @@ public class StringUtilities {
      * @return `input`
      */
     public String returnInput(String input) {
-        return null;
+
+        return input;
     }
 
     /**
@@ -14,7 +16,9 @@ public String returnInput(String input) {
      * @return the concatenation of `baseValue` and `valueToBeAdded`
      */
     public String concatenate(String baseValue, String valueToBeAdded) {
-        return null;
+        String baseVal = baseValue;
+        String output = baseVal.concat(valueToBeAdded);
+        return output;
     }
 
     /**
@@ -22,7 +26,13 @@ public String concatenate(String baseValue, String valueToBeAdded) {
      * @return identical string with characters in opposite order
      */
     public String reverse(String valueToBeReversed) {
-        return null;
+        // needed to add stringbuilder, no reason to use a costly for loop
+        StringBuilder str = new StringBuilder();
+        String input = valueToBeReversed;
+        str.append(input);
+        str.reverse();
+        String output = String.valueOf(str);
+        return output;
     }
 
     /**
@@ -30,7 +40,8 @@ public String reverse(String valueToBeReversed) {
      * @return middle character of `word`
      */
     public Character getMiddleCharacter(String word) {
-        return null;
+        char output = word.charAt((word.length())/2);
+        return output;
     }
 
     /**
@@ -39,7 +50,20 @@ public Character getMiddleCharacter(String word) {
      * @return `value` with char of value `charToRemove` removed
      */
     public String removeCharacter(String value, Character charToRemove) {
-        return null;
+        StringBuilder str = new StringBuilder();
+        String input = value;
+        int count = 0;
+        str.append(input);
+        for (int i =0 ; i < value.length(); i++) {
+            if ( value.charAt(i) == charToRemove) {
+                // output = value.replace(charToRemove.toString(), "");}
+                str.deleteCharAt(i-count);
+                // str.replace(i,i,"");
+                count += 1;
+            }
+        }
+        String output = String.valueOf(str);
+        return output;
     }
 
     /**
@@ -47,6 +71,9 @@ public String removeCharacter(String value, Character charToRemove) {
      * @return last `word` in sentence
      */
     public String getLastWord(String sentence) {
-        return null;
+        //StringBuilder str = new StringBuilder();
+        // str.append(sentence);
+        return sentence.substring(sentence.lastIndexOf(" ")+1);
+        // String output = String.valueOf(str);
     }
 }