added format

website/docs/eMath/E/e.md

@@ -12,6 +12,29 @@ The ``E`` function is the main feature of this package. It is based on [break_et
 Assuming that you already followed the instructions in the [usage guide](../../usage), you can use it as:
 ```js
 const { E } = eMath;
-const newNum2 = E(2300) // Number with value 2300
-console.log(newNum2.format()) // "2,300"
+
+const newNum2 = E(2300); // Number with value 2300
+newNum2; // 2300
+```
+
+The methods and functions are the same as breaK_eternity.js, which are the same as [Decimal.js](https://github.com/MikeMcl/decimal.js). For example,
+
+```js
+const { E } = eMath;
+
+const x = E(123.4567);
+const y = E('123456.7e-3');
+const z = E(x);
+x.equals(y) && y.equals(z) && x.equals(z); // true
+```
+
+To call methods, you can call ``E[method]``. For example,
+
+```js
+const { E } = eMath;
+
+const x = E(63);
+const y = E(7);
+
+E.divide(x, y); // E(9)
 ```

website/docs/eMath/E/format.md

@@ -0,0 +1,47 @@
+---
+id: format
+title: Format
+---
+
+---
+
+The ``E.format()`` function is the main way to convert ``E`` to a ``string``.
+
+### Usage
+
+After you create a new ``E``, you can call the ``format()`` method.
+```js
+const { E } = eMath;
+
+const newNum = E(2300); // Number with value 2300
+newNum.format(); // "2,300"
+```
+
+Alternatively, you can use the static ``E.format()`` method.
+```js
+const { E } = eMath;
+
+const newNum2 = E(2000); // Number with value 2000
+E.format(newNum2); // "2,300"
+```
+
+### Outputs
+
+After you reach 1,000,000,000 (1 billion), the format is automatically converted into letter form.
+
+```js
+const { E } = eMath;
+
+const newNum3 = E(1.23e9); // Number with value 1.23 billion
+E.format(newNum2); // "1.23 B"
+```
+
+After you reach 1e+300 (1 novemnonagintillion), the format is automatically converted into scientific form.
+
+```js
+const { E } = eMath;
+
+const newNum3 = E(1.32e303); // Number with value 1.23 billion
+E.format(newNum2); // "1.32e303"
+```
+

website/sidebars.js

@@ -30,6 +30,7 @@ const sidebars = {
                     label: "E",
                     items: [
                         "eMath/E/E",
+                        "eMath/E/format"
                     ],
                 },
                 {