Why does this concatenate instead of adding up

Question

Very very basic question but I\'ve got the following HTML:

Answer 1

Do I need to use parseInt or something?

Exactly. val() will return strings, which will get concatenated and not added up.

Do note that when using parseInt you should supply the radix parameter (second one) for the correct base - 10 for decimal, otherwise it will assume octal.

one = parseInt( $('#nspcc').val() , 10);