Been wanting to make this for a while A is for answer which stores the previous answer. Also you are allowed to add a number before the A like a variable so 2A is 2*A and 5A is 5*A. You can also do 8(2) which is 8*(2). Also you are able to have negative numbers so -5 is not blank minus 5. its -5. Im pretty sure this is just a calculator without all of the functions and extra variables (e/pi)