Warehouse counting

Hello. I'm newbie in creating apps. I'd like to create app which is needed in my work. The premise is this: When I open my warehouse have to count every item inside. All items are for example is 158. When I deselect ,,C 32" i want to subtract from 158 and results 128 etc. Can someone could help me with this? Thank you.

In its simplest form:

Thank you for reply. Ok but what about the rest A 32, I 34 etc? I want to everytime when all is selected to counts up all. And when i unselect 4 boxes then it subtracts from 158. Similarly when I want to sum up I select all 5 boxes. Very hard to explain because i dont speak english very well, but i believe you will understand me. Another thing is that I want to see my result everytime in label. Thank you one more time.
Also I need to connect it all in memory in some way.

To do all that you have to know how to handle how to use If statements Programming Your App to Make Decisions

What have you tried?

So I made it, but problem is that I have to sum from all 3 blocks not only one

When I hit the,,A" and ,,B" button it subtrackt sum from 96 and its shows sum 62 not 30. How to set this thing?

All I need it is subtracting from all checkboxes, not only from one, so if someone know how to make it please give me even small solution

When you reach three of something, it's easier to change the problem to the general problem of unlimited numbers.

Did you study the introductory lists links yet?

ABG please let me see part of this problem, what definitely should I look for? If I want solve up here my problem. Because you sent a lot of link for solve my problem, but I didn't see thing what can solve my problem anyway.

Start here.