In the eternal fight to teach math, teachers and parents need every trick in the book to keep kids interested. AddOrSubtract is a program that will help in the battle, with the added bonus that it's free!
AddOrSubtract is by no means a complex program - it has no help and no configuration options. It simply sets you addition and subtraction sums and records your answers in a given session. You can choose the range of both the top and bottom numbers in the sums - for example, you could tell AddOrSubtract to choose any number between 1 - 50 to be added to any number between 50 - 100, or whatever you want - which makes it appropriate for varying abilities.
That is literally all that AddOrSubtract does, so it is probably best used as part of a broader mathematics program. That said, it is simple to use and sets accurate problems, so it will definitely help put those math skills into practice.
AddOrSubtract provides very simple math practice.