JSFiddle - React, Tailwind, and code Playground

HTML

<input type='radio' id='feet' name='unit_of_measurement' onchange="change()" checked>Feet
<input type='radio' id='meters' name='unit_of_measurement' onchange="change()">Meters
<br />
<input type='number' id='select-number'>Pick A number

JavaScript

feet = document.getElementById('feet').checked;
meters = document.getElementById('meters').checked;
if (feet) {
    document.getElementById('select-number').max = 300;
    document.getElementById('select-number').step = 1;
} else {
    document.getElementById('select-number').max = 100;
    document.getElementById('select-number').step = .3;
}

function change() {
    feet = document.getElementById('feet').checked;
    meters = document.getElementById('meters').checked;
    if (feet) {
        document.getElementById('select-number').max = 300;
        document.getElementById('select-number').step = 1;
    } else {
        document.getElementById('select-number').max = 100;
        document.getElementById('select-number').step = .3;
    }
};