This app has helped my 4 year old daughter jump over a couple hurdles. After playing a couple times with me she understands the teens numbers now and doesnt miss thirteen anymore. When you finish sets of questions your progress bars fill up and you earn another "monster" or a new feature (smile, hat, etc.) to add to your existing monsters. She loves this and I think they have the reward system working perfectly.
bri_cowtown about Quick Math Jr., v1.4