class Button extends React. Component {
  handleClick = () => {
  	this.props.onClickFunction(this.props.incrementValue);
  };

	render() {
  return(
    <button
    onClick={this.handleClick}> + {this.props.incrementValue}</button>
    );
  }
}

const Result = (props) => {
	return (
    <div> {props.counter}</div>
    );
};

class App extends React.Component {
  state = {counter: 0};

  incrementCounter = (incrementValue) => {
  this.setState((prevState) => ({
  	counter: prevState.counter + incrementValue
    }));
  };

render() {
return (
<div>
<Button incrementValue={1} onClickFunction={this.incrementCounter} />
<Button incrementValue={5} onClickFunction={this.incrementCounter} />
<Button incrementValue={10} onClickFunction={this.incrementCounter} />
<Button incrementValue={100} onClickFunction={this.incrementCounter} />
<Result counter={this.state.counter}/>
</div>
);
}
}

ReactDOM.render(<App />, mountNode);