you have got to tell the scratch cat 2 numbers and then tell it to add, subtract, multiply or divide, and you can do that by typing 1,2,3 or 4. I guess if you look inside then you will get a better understanding.
All credit to me for the code, and Scratch for the art. This is mainly based on variables because there isn't really another way to store data. I made it because i thought that one day i might need to know a sum and i could just quickly jump on here and do it. Though you would need to know what type of math you are doing before so that you don't muck up your sum, like if you did 4-6 or something but wanted 6-4. You'll need to be careful of that.