diff --git a/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorDisplay.java b/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorDisplay.java
index 8c2621d..ca2252c 100644
--- a/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorDisplay.java
+++ b/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorDisplay.java
@@ -15,10 +15,10 @@ public static void menuOption1() {
                     System.out.println("Here are some Scientific Functions. \nSine() \nCosine() \nTangent()");
                     break;
                 case "3":
-                        String userInput = Console.getStringInput("Time for some math? \n ( Y / N )");
-                            if(userInput.equalsIgnoreCase("Y")) {
-                                break outerLoop;
-                            }
+                    String userInput = Console.getStringInput("Time for some math? \n ( Y / N )");
+                    if (userInput.equalsIgnoreCase("Y")) {
+                        break outerLoop;
+                    }
                     break;
                 default:
                     Console.println("[ %s ] is not a valid input!", prompt);
diff --git a/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorEngine.java b/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorEngine.java
index 315d5b4..c83459f 100644
--- a/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorEngine.java
+++ b/src/main/java/com/zipcodewilmington/scientificcalculator/CalculatorEngine.java
@@ -5,21 +5,57 @@ public class CalculatorEngine {
     private static Double value;
 
     public static Double sum(Double firstNum, Double secondNum) {
-        value = firstNum + secondNum;
-        return value;
+        return firstNum + secondNum;
     }
+
     public static Double subtract(Double firstNum, Double secondNum) {
-        value = firstNum - secondNum;
-        return value;
+              return firstNum - secondNum;
     }
 
     public static Double divide(Double firstNum, Double secondNum) {
-        value = firstNum / secondNum;
-        return value;
+        return firstNum / secondNum;
     }
 
     public static Double multiply(Double firstNum, Double secondNum) {
-        value = firstNum * secondNum;
+        return firstNum * secondNum;
+    }
+
+    public static Double squareRoot(Double firstNum){
+        double s;
+        double value = firstNum / 2;
+        do {
+            s = value;
+            value = (s +(firstNum / s)) / 2;
+        }
+        while ((s - value) != 0);
         return value;
     }
-}
+
+    public static Double square(Double firstNum){
+        return firstNum * firstNum;
+    }
+
+    public static Double squareY(Double firstNum, Double secondNum) {
+ return Math.pow(firstNum, secondNum);
+
+    }
+
+    public static Double squareRootY(Double firstNum, Double secondNum){
+        double xPre = Math.random() % 10;
+        double eps = 0.001;
+        double delX = 2147483647;
+        double xK = 0.00;
+       double A = firstNum;
+       double N = secondNum;
+
+
+        while (delX > eps){
+            xK = ((N - 1.0) * xPre + A / Math.pow(xPre, N - 1)) / N;
+            delX = Math.abs(xK - xPre);
+            xPre = xK;
+        }
+        double value = Math.round(xK * 1000.00) / 1000.00;
+        return value;
+        }
+
+    }
diff --git a/src/test/java/com/zipcodewilmington/scientific_calculator/CalculatorEngineTest.java b/src/test/java/com/zipcodewilmington/scientific_calculator/CalculatorEngineTest.java
index 7875439..fd83f0f 100644
--- a/src/test/java/com/zipcodewilmington/scientific_calculator/CalculatorEngineTest.java
+++ b/src/test/java/com/zipcodewilmington/scientific_calculator/CalculatorEngineTest.java
@@ -4,6 +4,8 @@
 import org.junit.Assert;
 import org.junit.Test;
 
+import static com.sun.tools.doclint.Entity.divide;
+import static com.zipcodewilmington.scientificcalculator.CalculatorEngine.*;
 
 
 public class CalculatorEngineTest {
@@ -11,10 +13,10 @@ public class CalculatorEngineTest {
     @Test
     public void testSum1() {
         // Given
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
+        CalculatorEngine CalculatorEngine = new CalculatorEngine();
         // When
         Double result;
-        result = calculatorEngine.sum(2.00, 2.00);
+        result = CalculatorEngine.sum(2.00, 2.00);
         // Then
         if (result != 4.00) {   // if 2 + 2 != 4
             Assert.fail();
@@ -23,10 +25,10 @@ public void testSum1() {
     @Test
     public void testSum2() {
         // Given
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
+        CalculatorEngine CalculatorEngine = new CalculatorEngine();
         // When
         Double result;
-        result = calculatorEngine.sum(1200.00, 500.00);
+        result = CalculatorEngine.sum(1200.00, 500.00);
         // Then
         if (result != 1700.00) {   // if 1200 + 500 != 1700
             Assert.fail();
@@ -59,38 +61,72 @@ public void testSubtract2() {
 
     @Test
     public void testDivide1() {
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
-        Double result;
-        result = calculatorEngine.divide(6.00, 3.00);
-        if (result != 2.00); {
-            }
+        Double expected = 100.00;
+        Double firstNum = 1000.00;
+        Double secondNum = 10.00;
+        Double actual = CalculatorEngine.divide(firstNum, secondNum);
+        Assert.assertEquals(expected, actual);
         }
 
     @Test
     public void testDivide2() {
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
-        Double result;
-        result = calculatorEngine.divide(33.33, 11.11);
-        if (result != 3.00); {
-        }
+        Double expected = 4.00;
+        Double firstNum = 20.00;
+        Double secondNum = 5.00;
+        Double actual = CalculatorEngine.divide(firstNum, secondNum);
+        Assert.assertEquals(expected, actual);
     }
 
     @Test
     public void testMultiply1() {
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
-        Double result;
-        result = calculatorEngine.multiply(5.00, 20.00);
-        if (result != 100.00); {
+        Double expected = 100.00;
+        Double firstNum = 20.00;
+        Double secondNum = 5.00;
+        Double actual = multiply(firstNum, secondNum);
+        Assert.assertEquals(expected, actual);
         }
-    }
+
 
     @Test
     public void testMultiply2() {
-        CalculatorEngine calculatorEngine = new CalculatorEngine();
-        Double result;
-        result = calculatorEngine.multiply(7.00, 20.00);
-        if (result != 140.00); {
-        }
+     Double expected = 4.00;
+     Double firstNum = 2.00;
+     Double secondNum = 2.0;
+     Double actual = multiply(firstNum, secondNum);
+     Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void testSquareRoot(){
+        Double expected = 2.00;
+        Double firstNum = 4.00;
+        Double actual = squareRoot(firstNum);
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void testSquare(){
+     Double expected = 16.00;
+     Double firstNum = 4.00;
+     Double actual = square(firstNum);
+     Assert.assertEquals(expected, actual);
+    }
+    @Test
+    public void testSquareY(){
+        Double expected = 7776.00;
+        Double firstNum = 6.00;
+        Double secondNumb = 5.00;
+        Double actual = CalculatorEngine.squareY(firstNum, secondNumb);
+        Assert.assertEquals(expected, actual);
+    }
+
+    @Test
+    public void testSquareRootY(){
+        Double expected = 1.431;
+        Double firstNum = 6.00;
+        Double secondNumb = 5.00;
+        Double actual = CalculatorEngine.squareRootY(firstNum, secondNumb);
+        Assert.assertEquals(expected, actual);
     }
 }