This app is great for kids to learn simple mathematical operations as addition, subtraction, multiplication, division. Fully free. Enjoy and make kids educational progress become much faster.
https://itunes.apple.com/us/app/math-for-kids!-simple-operations/id806817016?ls=1&mt=8
https://itunes.apple.com/us/app/math-for-kids!-simple-operations/id806817016?ls=1&mt=8