Divisibility

Know instantly whether a number divides cleanly.

• 1Divisible by 3 or 9?Add up the digits — the answer is hiding in the total. 4 practice questions+15 XP
• 2Divisible by 4 or 8?Ignore the whole number — only the last digits matter. 4 practice questions+15 XP
• 3Divisible by 11?Add alternate digits, subtract the two groups, look for 0 or 11. 3 practice questions+20 XP