How to use onChange and onClick event in React JS?

import React, { Component } from 'react';
 
class App extends Component {
  constructor() {
    super();
 
    this.state = {
      number1: 0,
      number2: 0,
      result: 0
    };
  }
 
  handleOnChange = e => {
    const { target: { value, name } } = e;
 
    this.setState({
      [name]: Number(value)
    });
  }
 
  handleResult = e => {
    this.setState({
      result: this.state.number1 + this.state.number2
    });
  }
 
  render() {
    return (
      <div className="Calculator">
        <input onChange={this.handleOnChange} name="number1" type="text" value={this.state.number1} />
        {' + '}
        <input onChange={this.handleOnChange} name="number2" type="text" value={this.state.number2} />
        <p><button onClick={this.handleResult}>=</button></p>
 
        <p className="result">{this.state.result}</p>
      </div>
    );
  }
}
 
export default App;