product total dynamic update

[gugush]

Hello. I am very much familiar with ZenCart , and was very successfully using it for last 1 year for a t-shirt store. Now i have a new site to put together and i was wondering how this following can be done.
on main page where all products are listed to have 3 fields near each product. I could figure out 2 out of 3. and need to learn a bit.
1st field - products unit price. 2nd field- fillable quantity that customer need to type how many of this products units he needs (i could figure out this). 3rd field that i am asking for help is - unit total dynamically calculated, based on 1st and 2nd field. if i have 10 different products on one page, and customer selects products, input quantityes he sees totals and per units infront of each product, and on the bottom of the page he sees all totals.
is where some addon available to do this? any help would be very appretiated. thanks!

[gugush]

could not figure out how to edit this my post, so adding image that visually explains what exactly i am asking. thanks.