modules example added

02_Day_Introduction_to_React/02_introduction_to_react.md

@@ -11,8 +11,6 @@
 <a href="https://www.linkedin.com/in/asabeneh/" target="_blank">Asabeneh Yetayeh</a><br>
 <small> October, 2020</small>
 </sub>
-
-</div>
 </div>
 
 [<< Day 1](../01_Day_JavaScript_Refresher/01_javascript_refresher.md) | [Day 3 >>](../03_Day_Setting_Up/03_day_setting_up.md)

03_Day_Setting_Up/03_day_setting_up.md

@@ -68,15 +68,34 @@ In react we do not use link to access modules or packages instead we import the
 export const addTwo = (a, b) => a + b
 export const multiply = (a, b) => a * b
 export const subtract = (a, b) => a - b
-default export doSomeMath = () => {
+
+export default (function doSomeMath() {
   return {
-    addTwo, multiply, subtract
+    addTwo,
+    multiply,
+    subtract,
   }
+})()
+```
 
-}
+Now let's import the _math.js_ modules to a different file.
+
+```js
+// index.js
+// to import the doSomeMath from the math.js with or without extension
+import doSomeMath from './math.js'
+
+// to import the other modules
+// since these modules were not exported as default we have to desctructure
+import { addTwo, multiply, subtract } from './math.js'
+
+import * as everything from './math.js' // to import everything renaming
+console.log(addTwo(5, 5))
+console.log(doSomeMath.addTwo(5, 5))
+console.log(everything)
 ```
 
-Now let's import the _math.js_ modules to a different file
+After this, when you see _import React from 'react'_ or _import ReactDOM from 'react-dom'_ you will not be surprised.
 
 ## Package