Keep Prime Numbers

Remove all the blocks to make the composite number going out but keep the prime number. Click or tap the unused block to drop the composite numbers.

Tap on the blocks that are composite to clear them from the grid. Steer clear of the prime numbers as they must remain on the grid. Apply your knowledge of number types to strategically choose which numbers to remove. Advance by eliminating all non-primes from each level. Pay attention to the increasing difficulty as you advance through the rounds. Train your number recognition to improve your accuracy.