diff --git a/day02/src/com/inmind/yunsuan02/Demo09.java b/day02/src/com/inmind/yunsuan02/Demo09.java
new file mode 100644
index 0000000..4cb53bc
--- /dev/null
+++ b/day02/src/com/inmind/yunsuan02/Demo09.java
@@ -0,0 +1,25 @@
+package com.inmind.yunsuan02;
+/**
+ 赋值运算符：+= -= *= /= %=
+  a = b;
+  a += b;
+ 混合赋值运算符：先将左边的变量与右边的数值进行对应的运算，将运算结果赋值给左边的变量
+
+ */
+public class Demo09 {
+    public static void main(String[] args) {
+        int i = 10;
+        i-=10;//i = i+10;
+        System.out.println(i);//20
+
+        int j = 20;
+        j -= 5;//j = j-5;
+        System.out.println(j);//15
+
+        int k = 10;
+        //针对k除以2，取余数
+//        k = k%2;
+        k %= 2;
+        System.out.println(k);//0
+    }
+}