Use capital X for times, / for divide, + for add, and - for subtract. Like a real calculator, this uses negative numbers and decimals. You can use numbers a big as you want.
This is a cool project I decided to make. Believe it or not, it wasn't that difficult. This simple device can calculate any numbers by any of the four main operations. Feel free to look inside to see how it works! (You can't do that with a real-life one!)
