Guess the 4-digit prime number in 6 tries. Your guess can be any 4-digit number — it doesn't have to be prime.
After each guess the tiles show how close you are:
Green — right digit, right position.
Yellow — digit is in the answer but in a different spot.
Gray — digit is not in the answer.
After 2 guesses a ? hint button unlocks in the header. One hint per puzzle. A Math fun note appears after each guess. A new prime drops every day.