React Native how to pass the value from component to the main activity without using Redux?

How to / Third Party Tooling
1

I am making a upload product for selling . And I had make a component for receive the input number(units or price) from the user, and in the main page will need to count the total price : units * price … However ,I get stucked here … I don’t know how I am able to get the value from the component …

I have attached my code . Could you please take a look ? Thank you so much !!

Component for putting number

import React from 'react';
import { StyleSheet, View } from 'react-native'
import { TextInput } from 'react-native-gesture-handler';
import colors from '../config/colors';

function TryInputNum({children}) {
    return (
        <View style={styles.container}>
            <TextInput placeholder="Enter a number">{children}</TextInput>
        </View>
    );
}

const styles = StyleSheet.create({
    container :{
        width : 150,
        height : 200,
        backgroundColor : colors.white,
    }
})
export default TryInputNum;

The main page

import React from 'react';
import { StyleSheet, View,Text } from 'react-native'
import TryInputNum from '../components/TryInputNum';
import colors from '../config/colors';

function TryCountScreen({children}) {
    return (
        <View style={styles.container}>
            <Text>{children}</Text>
           <TryInputNum/> 
        </View>
    );
}

const styles = StyleSheet.create({
    container : {
        flex :1,
        backgroundColor : colors.primary,
        justifyContent : 'center',
        alignItems : 'center',
    }
})
export default TryCountScreen;