diff --git "a/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/a.js" "b/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/a.js"
new file mode 100644
index 0000000000000000000000000000000000000000..6964065b39484a37838ac777d8269776194e5edd
--- /dev/null
+++ "b/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/a.js"
@@ -0,0 +1,23 @@
+//加
+let aa=function(a,b){
+    console.log(a+b);
+}
+//减
+let bb=function(a,b){
+    console.log(a-b);
+}
+//乘
+let cc=function(a,b){
+    console.log(a*b);
+}
+//除
+let dd=function(a,b){
+    console.log(a/b);
+}
+let obj={
+    a:aa,
+    b:bb,
+    c:cc,
+    d:dd
+}
+module.exports=obj;
diff --git "a/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/b.js" "b/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/b.js"
new file mode 100644
index 0000000000000000000000000000000000000000..6ef9a1e01eb2799fcd3aa0df101835219729d929
--- /dev/null
+++ "b/\344\275\225\345\277\227\351\271\217/2.21\347\254\254\344\270\200\346\254\241\344\275\234\344\270\232/demo1/b.js"
@@ -0,0 +1,15 @@
+let a=1;
+let b=2;
+
+//引入
+let aa=require('./a');
+
+
+//加
+let no1=aa.a(a,b)
+//减
+let no2=aa.b(a,b)
+//乘
+let no3=aa.c(a,b)
+//除
+let no4=aa.d(a,b)
\ No newline at end of file