JSFiddle - React, Tailwind, and code Playground

HTML

<input id="first" value="0.5"> + <input id="second" value="0.7"> = <input id="result"><br>

The problem:<br>
Try 0.1 + 0.2, it does not equal to 0.3<br>
0.01 + 0.06 does not equal to 0.07

CSS

input{
    width:50px;
}

JavaScript

function roundNumber(number, decimals) {
    var newnumber = new Number(number+'').toFixed(parseInt(decimals));
    return parseFloat(newnumber); 
}
function add(){
    $result = (+$("#first").val())+(+$("#second").val());
    $("#result").val(roundNumber($result, 12));
}
add();
$("input").blur(add);