Fast Pattern Drill
Prime Speed Check
Decide as quickly as you can whether each number is prime. Pick a preset range or build your own, then race through the stream one number at a time.
Choose a Level
Medium is selected by default.
Current Range
0-120
Last Result
Press Start Round to begin.
How It Works
Prime numbers are greater than 1 and divisible only by 1 and themselves. In this challenge, 0 and 1 count as not prime.