diff --git a/src/java2020spring/CalculatorFrame.java b/src/java2020spring/CalculatorFrame.java
new file mode 100644
index 0000000000000000000000000000000000000000..8dd3365f08334f1cbbda9bb05baf8fd308fd522d
--- /dev/null
+++ b/src/java2020spring/CalculatorFrame.java
@@ -0,0 +1,130 @@
+package java2020spring;
+import java.awt.Container;
+import java.awt.Dimension;
+import java.awt.FlowLayout;
+import java.awt.GridLayout;
+import java.awt.event.ActionEvent;
+import java.awt.event.ActionListener;
+import javax.swing.*;
+public class CalculatorFrame extends JFrame{ 
+	 JPanel p1 = new JPanel(); 
+	 JPanel p2 = new JPanel(); 
+	 JTextField cal;
+	 String lastCommand="=";
+	 StringBuffer str; 
+	 int x,y; 
+	 double result;  
+	 boolean start=(true);
+	 JButton b[] = new JButton[12];  
+	 JButton b1,b2,b3,b4,b5,b6,b7,b8,b9,b10,b11,b12,b13; 
+	public CalculatorFrame() { 
+	 Container page = getContentPane(); 
+	 cal= new JTextField(45); 
+	 cal.setBounds(30, 50, 220, 20);
+	 cal.setEditable(false);
+	 p2.add(cal); 
+	 p2.setLayout(new GridLayout(5,1)); 
+	 for(int i=0;i<10;i++) 
+	 {String s=""+i; 
+	 b[i]= new JButton(s); 
+	 b[i].addActionListener(new NumListener()); 
+	 } 
+	b[10]= new JButton("-/+"); b[11]= new JButton("."); 
+	 b1= new JButton("/"); b2= new JButton("Back"); 
+	 b3= new JButton("*"); b4= new JButton("C"); 
+	 b5= new JButton("+"); b6= new JButton("Sqrt"); 
+	 b7= new JButton("-"); b8= new JButton("="); 
+	 b9=new JButton("MC");b10=new JButton("MR");
+	 b11=new JButton("MS");b12=new JButton("M+");
+	 b13=new JButton(" ");
+	p1.add(b1);p1.add(b2);p1.add(b3);p1.add(b4);p1.add(b5);p1.add(b6);p1.add(b7);p1.add(b8); p1.add(b9);p1.add(b10);p1.add(b11);p1.add(b12);p1.add(b13);
+	p1.add(b9);p1.add(b10);p1.add(b11);p1.add(b12);p1.add(b13);
+	p1.add(b[7]); p1.add(b[8]); p1.add(b[9]); p1.add(b1); p1.add(b2); 
+	p1.add(b[4]); p1.add(b[5]); p1.add(b[6]); p1.add(b3); p1.add(b4); 
+	p1.add(b[1]); p1.add(b[2]); p1.add(b[3]); p1.add(b5); p1.add(b6); 
+	p1.add(b[10]);p1.add(b[0]);p1.add(b[11]);p1.add(b7);p1.add(b8); 
+	 Dimension preferredSize = new Dimension(85, 95);
+	 b1.setPreferredSize(preferredSize);
+	 p1.setLayout(new GridLayout(5,5,5,5)); 
+	 b[10].addActionListener(new CalListener()); b[11].addActionListener(new NumListener()); 
+	 b1.addActionListener(new CalListener()); b2.addActionListener(new CalListener()); 
+	 b3.addActionListener(new CalListener()); b4.addActionListener(new CalListener()); 
+	 b5.addActionListener(new CalListener()); b6.addActionListener(new CalListener()); 
+	 b7.addActionListener(new CalListener()); b8.addActionListener(new CalListener()); 
+	 b9.addActionListener(new CalListener()); b10.addActionListener(new CalListener()); 
+	 b11.addActionListener(new CalListener()); b12.addActionListener(new CalListener()); 
+	 page.add(p2); 
+	 page.add(p1); 
+	 page.setLayout(new FlowLayout()); 
+	 setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);  
+	 setVisible(true); 
+	 setResizable(false); 
+	}
+	
+	private class NumListener implements ActionListener {
+
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            String num = e.getActionCommand();
+            if (start) {
+                cal.setText(num);
+                start = false;
+            }
+            else
+            	cal.setText(cal.getText()+num);         
+        }   
+    }
+	
+	private class CalListener implements ActionListener {
+
+        @Override
+        public void actionPerformed(ActionEvent e) {
+            start = true;
+            String command = e.getActionCommand();
+            double x = Double.parseDouble(cal.getText());
+            if (lastCommand.equals("+"))
+                result += x;
+            else if (lastCommand.equals("-"))
+                result -= x;
+            else if (lastCommand.equals("*"))
+                result *= x;
+            else if (lastCommand.equals("/"))
+                result /= x;
+            else if (lastCommand.equals("="))
+            	result = (int) x;
+            else if(lastCommand.equals("C"))
+            	result=0;
+            else if(lastCommand.equals("MC"))
+            	result =0;
+            else if(lastCommand.equals("M+"))
+                result=(int) Double.parseDouble(cal.getText());
+            else if(lastCommand.equals("MR"))
+            	result=(int) Double.parseDouble(cal.getText());
+            else if(lastCommand.equals("MS"))
+            	result=(int) Double.valueOf(cal.getText()).doubleValue();
+            cal.setText(""+result);
+            lastCommand = command;
+            if(lastCommand.equals("-/+")){
+                x=0- Double.parseDouble(cal.getText().trim());
+                cal.setText(""+x); }
+            if(lastCommand.equals("Sqrt")) {
+                if(x>=0){
+                	cal.setText(String.valueOf(Math.sqrt(x)));}
+                else {cal.setText("负数不能开平方根");}
+                }
+        	if(lastCommand.equals("Back")){
+            if(Double.parseDouble(cal.getText()) > 0){
+             if(cal.getText().length()> 1){
+              cal.setText(cal.getText().substring(0, cal.getText().length()-1));
+             }else{ cal.setText("0"); }
+            }else{
+            	if(cal.getText().length() > 2){
+              cal.setText(cal.getText().substring(0,cal.getText().length()-1));
+             }else{
+              cal.setText("0");
+             }
+	}}}}}
+           
+	
+        
+
diff --git a/src/java2020spring/MainCalculator.java b/src/java2020spring/MainCalculator.java
new file mode 100644
index 0000000000000000000000000000000000000000..c2cbd7d6a0ef82a5fbfce9d03b7d492014c28448
--- /dev/null
+++ b/src/java2020spring/MainCalculator.java
@@ -0,0 +1,38 @@
+package java2020spring;
+
+import java.awt.Color;
+import java.awt.Container;
+import javax.swing.JFrame;
+import javax.swing.JMenu;
+import javax.swing.JMenuBar;
+import javax.swing.JMenuItem;
+public class MainCalculator {
+	public static void main(String args[]) {
+		CalculatorFrame calculator=new CalculatorFrame();
+		calculator.setTitle("标准型计算器");
+		Container con=calculator.getContentPane();
+		con.setBackground(Color.white);
+		calculator.setBounds(250, 100, 500, 700);
+		JMenuBar menubar = new JMenuBar();
+		JMenu edit = new JMenu("编辑");
+		JMenu check = new JMenu("查看");
+		JMenu help = new JMenu("帮助");
+		JMenuItem copy = new JMenuItem("复制");
+		JMenuItem formal = new JMenuItem("标准型");
+		JMenuItem scient = new JMenuItem("科学型");
+		JMenuItem message = new JMenuItem("帮助信息");
+		edit.add(copy);
+		check.add(formal);
+		check.addSeparator();
+		check.add(scient);
+		help.add(message);
+		menubar.add(edit);
+		menubar.add(check);
+		menubar.add(help);
+		calculator.setJMenuBar(menubar);
+		calculator.setVisible(true);
+		calculator.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
+		calculator.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
+		calculator.setVisible(true);
+	}
+}
diff --git a/src/java2020spring/Test.java b/src/java2020spring/Test.java
deleted file mode 100644
index fc09c195f566d0e707f5e8a2f05fd168069c73a7..0000000000000000000000000000000000000000
--- a/src/java2020spring/Test.java
+++ /dev/null
@@ -1,10 +0,0 @@
-package java2020spring;
-
-public class Test {
-
-	public static void main(String[] args) {
-		System.out.println("Hello world!");
-
-	}
-
-}