Yes it is possible using Javascript.
Here is link to a working fiddle example.
There are three divs, each with the same class and containing a unique value.
<div class="cell">10</div>
<div class="cell">20</div>
<div class="cell">30</div>
jQuery is used to select all the elements with the class "cell" and then get the text, convert it to a number (an integer in this case) and sum the values.
var sum=0
$(".cell").each(function(i) {
sum = sum + parseInt($(this).text());
});
console.log(sum)
The final sum is printed to the browser console.
Edit:
Here is an edited fiddle where the sum is added to the webpage using jQuery's append function.