I think it would be great to have a point/star system in place so when the children finish the different areas they "earn" a reward. Other programs have children earn stars or points for correct answers and when they get soo many they can go to a "game" area where they can "spend" their points/stars. This would motivate the children to keep workin!!
Ashley Dickinson commented
Kids would like to earn stars, coins, etc. I agree with that part. However, in other apps, I don't like that they can often sneak into the reward zone and spend all their time there, rather than practicing math. I think it should just be coins/stars with no actual reward zone or the reward zone should have some type of timer that boots them out after a specific amount of time.