Primary Krypto

  • Primary Krypto

    Grade: PreK to 2nd, 3rd to 5th, 6th to 8th

    The rules of Krypto are simple: Combine five number cards using the four arithmetic operations (+, –, ×, ÷) to arrive at a "target" number. This online version of Primary Krypto uses the numbers 1–10 only.



    • Drag-and-drop the number cards onto the game board. They will snap into place on the outlined squares. From the small squares, choose which operation is to be performed.
    • The three buttons are used to control the game:
      • deal - get a new set of number cards and a new target number
      • hint - for the current hand, reveal one possible set of operations that yield a solution
      • solve - see our solution (though not necessarily the only solution)


      • Click deal to generate a set of number cards and a target number. Find a solution for the puzzle. Then, click the hint button if you did not find our solution. Can you find a solution that uses the operations in the order supplied by the hint?
      • What problem-solving strategies can be used while playing Primary Krypto?

      Objectives and Standards

      NCTM Standards and Expectations
      • Number and Operations
      • Pre-K - 2
      • 3-5
      • 6-8
      • Number and Operations