Learning a number system can be tricky, especially if you're 4 and just getting a concept of what numbers are. This project is aimed toward making learning numbers, and math in general, fun for small children, while making it easy to grasp from the first minute they have their hands on the widget.
The project started as a "birthday present" for my niece's 2nd birthday. Then a Christmas present. Then a gift for her 3rd birthday... and now she's going to be 5 and I figure it would be a good time to finish it.
The calculator is essentially 4 buttons from a calculation: One button will increment Variable A, another increments Variable B, then the user would selection the type of operation (Add, subtract, Divide, Multiply) and then hit the big red button in the middle to execute the operation.