Calculator.js

import React from 'react';
import Button from '@material-ui/core/Button';
import '../node_modules/bootstrap/dist/css/bootstrap.min.css';
import '../node_modules/bootstrap/dist/js/bootstrap.bundle';

const Calculator = () => {
    return (
        <>
            <div className="container">
                <h1>Hello World</h1>
                <Button variant="contained" color="primary">
                    Hello World
                </Button>
            </div>
        </>
    );
}

export default Calculator;