My JavaScript is adding inputs as strings. How can I turn them into integers to give me a correct total amount?

<!DOCTYPE html>
	<title>This is a test</title>
<form id="form1">
	Size: <input type="number" name="sizes" size="10"><br>
	Bow: Yes<input type="radio" name="bow" value=5 />
				No <input type="radio" name="bow" value=0 /><br>
	Stern: Yes<input type="radio" name="stern" value=5 />
				No<input type="radio" name="stern" value=0 />
<button onclick="outputsize()">Submit</button>
function outputsize() {
	var x,y,b,s,sizes;

	x=document.getElementById("form1") ;
	document.getElementById("demo").innerHTML=(y * 2+b+s);



<h1 id="demo"></h1>

maybe use something like parseInt ?

Thank you. I was wondering how to make the post viewable.

The Number Function did the trick. I was at a lost, but that makes complete sense.. Thank you so much for the helpful advice.

Thank you for your suggestion. Using the Number Function was able to get me the result I was looking for.