About Factor Forest
Factor Forest is about the building blocks of numbers. In Prime catch, numbers fall from the sky and you tap the primes before they land, while leaving composite numbers alone; primes of 50 or more are golden and go into your collection. The game never forgets the two classic traps: 1 is not a prime, and 2 is the only even prime.
In Factor trees you split a number like 60 into two factors, then keep splitting until every leaf is prime: 60 = 2 × 2 × 3 × 5. Whatever split you start with, the leaves always come out the same, because every whole number above 1 has just one set of prime factors. Each finished tree is planted in your forest.
The sieve is the Sieve of Eratosthenes on a hundred square: tap 2, 3, 5 and 7 in turn and watch their multiples disappear, leaving the 25 primes up to 100. Tiles and buses uses the highest common factor to find the biggest square tile for a floor, and the lowest common multiple to find when two buses next leave together.
Best for ages 9+
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