index.html
<!DOCTYPE html>
<html lang="ja">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>My JavaScript</title>
</head>
<body>
<script src="main.js"></script>
</body>
</html>main.js
'use strict';
/*
Javascriptにおける数値の表現
*/
// console.log(150 * 120 * 1.1);
// console.log(150 - 130 * 1.1);
// console.log(150 * 140 * 1.1);
//変数
let price;
//定数
const rate = 1.1;
price = 150;
console.log(price * 120 * rate);
console.log(price * 130 * rate);
console.log(price * 140 * rate);
price++;
console.log(price * 120 * rate);
console.log(price * 130 * rate);
console.log(price * 140 * rate);