Number Games
Number Games
Prime Sorter
Sort numbers as prime or composite and inspect a factor when a number is composite.
On phones, tap × to return
How to play
- Decide whether the displayed whole number has exactly two positive factors.
- Choose Prime or Composite.
- Use the factor feedback to check composite decisions and complete twelve numbers.
What this game practices
Useful for applying a definition and checking divisibility. It deliberately includes 1, which is neither composite nor prime, and explains that exception rather than forcing it into a false binary category.
How we checked it
Original coolmath game. Classification is computed locally by testing whole-number divisors through the square root, and composite feedback displays an actual factor pair.
Reviewed by coolmath Editorial Team · Updated 2026-10-09