diff --git a/src/simplejavacalculator/Calculator.java b/src/simplejavacalculator/Calculator.java
index 18ad91c..51e1fb8 100644
--- a/src/simplejavacalculator/Calculator.java
+++ b/src/simplejavacalculator/Calculator.java
@@ -15,6 +15,7 @@
 import static java.lang.Math.log;
 import static java.lang.Math.log10;
 import static java.lang.Math.pow;
+import static java.lang.Math.exp;
 
 public class Calculator {
 
@@ -23,7 +24,7 @@ public enum BiOperatorModes {
     }
 
     public enum MonoOperatorModes {
-        square, squareRoot, oneDividedBy, cos, sin, tan ,log , rate, abs
+        square, squareRoot, oneDividedBy, cos, sin, tan ,log , rate, abs, fact, e 
     }
 
     private Double num1, num2;
@@ -118,7 +119,15 @@ public Double calculateMono(MonoOperatorModes newMode, Double num) {
         if (newMode == MonoOperatorModes.abs){
             return Math.abs(num);
         }
-
+        if (newMode == MonoOperatorModes.fact) {
+            int fact = 1;   
+            for(int i = 1;i <= num; i++) {    
+                fact=fact*i;    
+            }   
+        }
+        if (newMode == MonoOperatorModes.e) {
+            return Math.exp(num);  
+        }
         // never reach
         throw new Error();
     }
diff --git a/src/simplejavacalculator/UI.java b/src/simplejavacalculator/UI.java
index 8e9cc4a..a2f98e7 100644
--- a/src/simplejavacalculator/UI.java
+++ b/src/simplejavacalculator/UI.java
@@ -51,7 +51,7 @@ public class UI implements ActionListener {
    private final JTextArea text;
    private final JButton but[], butAdd, butMinus, butMultiply, butDivide,
       butEqual, butCancel, butSquareRoot, butSquare, butOneDividedBy,
-      butCos, butSin, butTan, butxpowerofy, butlog, butrate, butabs, butBinary;
+      butCos, butSin, butTan, butxpowerofy, butlog, butrate, butabs, butBinary, butFact, butE;
    private final Calculator calc;
    
    private final String[] buttonValue = {"0", "1", "2", "3", "4", "5", "6",
@@ -105,7 +105,9 @@ public UI() throws IOException {
       butrate = new JButton("x%");      
       butabs = new JButton("abs(x)");      
       butCancel = new JButton("C");      
-      butBinary = new JButton("Bin");      
+      butBinary = new JButton("Bin"); 
+      butFact = new JButton("x!"); 
+      butE = new JButton("e^x"); 
       
       calc = new Calculator();
       
@@ -141,6 +143,8 @@ public void init() {
       butabs.setFont(font);
       butCancel.setFont(font);
       butBinary.setFont(font); 
+      butFact.setFont(font); 
+      butE.setFont(font); 
       
       panel.add(Box.createHorizontalStrut(100));
       panelSub1.add(text);
@@ -166,8 +170,11 @@ public void init() {
       panelSub4.add(but[8]);
       panelSub4.add(but[9]);
       panelSub4.add(Box.createHorizontalStrut(15));
+      panelSub4.add(butFact);
+      panelSub4.add(butE);
       panelSub4.add(butEqual);
       panelSub4.add(butCancel);
+      
       panel.add(panelSub4);
       
       panelSub5.add(Box.createHorizontalStrut(92));
@@ -211,6 +218,8 @@ public void init() {
       butabs.addActionListener(this);
       butBinary.addActionListener(this);
       
+      butFact.addActionListener(this);
+      butE.addActionListener(this);
       butEqual.addActionListener(this);
       butCancel.addActionListener(this);
       
@@ -288,6 +297,12 @@ public void actionPerformed(ActionEvent e) {
 
          if (source == butabs)
             writer(calc.calculateMono(Calculator.MonoOperatorModes.abs, reader()));
+         
+         if (source == butFact)
+            writer(calc.calculateMono(Calculator.MonoOperatorModes.fact, reader()));
+         
+         if (source == butE)
+            writer(calc.calculateMono(Calculator.MonoOperatorModes.e, reader()));
 
          if (source == butEqual)
             writer(calc.calculateEqual(reader()));
diff --git a/src/simplejavacalculatorTest/CalculatorTest.java b/src/simplejavacalculatorTest/CalculatorTest.java
index 1ea20f7..082e6c4 100755
--- a/src/simplejavacalculatorTest/CalculatorTest.java
+++ b/src/simplejavacalculatorTest/CalculatorTest.java
@@ -115,5 +115,21 @@ void CalculateMonoAbsTest() {
 		Assertions.assertEquals(3.0, calculator.calculateMono(Calculator.MonoOperatorModes.abs, -3.0));
 		Assertions.assertEquals(3.0, calculator.calculateMono(Calculator.MonoOperatorModes.abs, 3.0));
 	}
+	
+	@Test
+	void CalculateMonoFactTest() {
+		Calculator calculator = new Calculator();
+		Assertions.assertEquals(6, calculator.calculateMono(Calculator.MonoOperatorModes.fact, 3.0));
+		Assertions.assertEquals(120, calculator.calculateMono(Calculator.MonoOperatorModes.fact, 5.0));
+	}
+	
+	@Test
+	void CalculateMonoFactE() {
+		Calculator calculator = new Calculator();
+		Assertions.assertEquals(1, calculator.calculateMono(Calculator.MonoOperatorModes.e, 0.0));
+		Assertions.assertEquals(54.59815003, calculator.calculateMono(Calculator.MonoOperatorModes.e, 4.0));
+	}
+	
+	
 
 }