HTML5 output tag http://www.sansys.net/2014/07/html5-output-

<form oninput="x[x.hasOwnProperty('value') ? 'value' : 'innerHTML'] = parseInt(a.value) + parseInt(b.value||0)" onsubmit="return false">0
    <input type="range" id="a" value="50">100
    +<input type="number" id="b" value="50">
    =<output name="x"  for="a b">100</output>
</form>
<!--so.. we starts!--!>