ArithMate app for iPhone and iPad

Arithmetic is the foundation of Mathematics. Being able to do arithmetic calculations quickly and mentally is a valuable skill.  ArithMate is designed to help students (Grade 5 onwards) develop mental arithmetic skills. It comprises lessons and a game. The lessons teach easy methods to add, subtract, multiply and divide small and large numbers; while the game will allow users to practise the methods explained in the lessons.

From the configurations page, one can choose problems on any one of the four mathematical operations (+,-, x, /), or a combination of operations. The game starts with easy problems and gradually increases in difficulty.