JSFiddle - React, Tailwind, and code Playground

JavaScript

var a = 12.24;
console.log(roundHalf(a));
var b = 12.27;
console.log(roundHalf(b));
var result = roundHalf(a) + roundHalf(b);
console.log(result);

function roundHalf(num){
    return Math.ceil(num * 2) / 2;
}