JSFiddle - React, Tailwind, and code Playground
by hcanning2012
HTML
<div id="one">1</div>
<div id="two">8</div>
<div id="total">0</div>
JavaScript
var one = document.getElementById('one'),
two = document.getElementById('two'),
total = document.getElementById('total');
total.innerHTML = parseInt(one.innerHTML) + parseInt(two.innerHTML);