Participate in the substraction contest. Getthe fastest time and compete with your friends on Facebook, Twitterand other social networks to see who is the fastest in the art ofsubstracting.

Have 3 difficulty levels and each level will be more difficultoperations.

Join the fun game of substracting and exercise your mind.

Ideal also for people who for various reasons have to exerciseyour mind. Do not let your brain atrophy and put them up.