Cost: Free 3rd Grade, 4th Grade, 5th Grade, 6th Grade, 7th Grade, 8th Grade
It's like Fruit Ninja, except that instead of slashing fruit, the player slashes composite numbers until they are prime. Points are awarded for correctly slashing composite numbers. Players lose a life for each time they slash a prime number. Players start with 3 lives. There are 3 levels of difficulty: grasshopper, apprentice, and master.
When composite numbers are slashed, they break into 2 factors. If one of the factors is still a composite number, it must be slashed into it's factors before falling from view or else points are deducted from the player's score. Students become more aware of the factors that make up numbers, and unwittingly become better at multiplication and division as a result.