Two way binding and wiring an onChange for a child class

I'm new to react and its design pattern, so i tried writing a two way binding and create an onChange for my class and its child, and i was wondering if this is a good thing to do and if its the correct design pattern

I have done something like this :

class A extends Component {
    state = {
        BClassProperties: {
            goldAmount: '1',
            silverAmount: '2'
        }
    }

    onBChange = (goldAmount, silverAmount) => {
        const oldBClassProperties = this.state.BClassProperties;

        let newBClassProperties = {...oldBClassProperties};

        newBClassProperties.goldAmount = goldAmount;
        newBClassProperties.silverAmount = silverAmount;

        this.setState({BClassProperties: newBClassProperties})
    }

    render () {
        return (
           <B 
              goldAmount = {this.state.goldAmount} 
              silverAmount = {this.state.silverAmount} 
              onChange={this.onBChange}
           />
        )
    }
}

class B extends Component {

onGoldChange = (event) => {
    this.props.onChange(event.target.value, this.props.silverAmount);
};

onSilverChange = (event) => {
    this.props.onChange(this.props.goldAmount, event.target.value);
};

render () {

    return (
        <React.Fragment>
            <input placeholder={"gold"} onChange={this.onGoldChange} />
            <input placeholder={"silver"} onChange={this.onSilverChange} />
        </React.Fragment>
    )
}
}  

Is this okay?, are there any better alternatives ?
Thanks.