Calculations in dymanic data binding

Hi Guys,

I’ve got a form at the moment which adds up a bunch of input, I’m wanting to create a grand total at the bottom.

What I’ve got so far is a number of input fields which the user inputs numbers into.

At the bottom of the form I have another input field which I’ve added a dymanic attribute to and i’m just “+”’ (adding) all of the input.value’s up in a data binding - problem is that it doesnt actually add the number up - it just adds it to the end (eg. input1.value is 5 and input2.value is 6 - Instead of showing 11 it shows 56)

Is there any way to do a sum on all of these fields?

Thanks in advance

Ben