When I was in high school, we did various projects including:

- a pizza shop's register software. It doesn't have to be complex, but it will demonstrate how they can build a menu system and compute some simple costs for toppings and delivery costs.

- compute some mathematical formulas: like American to metric conversions, area, volume for various shapes. It should use a menu system so that users can select the type of computation and be prompted for inputs.

j