Divisibility Rules for Kids: 2, 3, 5, 9, 10
Divisibility rules let you check a result in seconds without doing the actual division. Five rules and any number becomes transparent.
Why divisibility rules matter
Is 354 divisible by 3? You could divide in a column — slow. The rule for 3 answers in a second: add the digits. 3+5+4=12; 12 divides by 3, so 354 does too. Rules save time and reveal number structure.
The five rules
Divisible by 2
The last digit is even: 0, 2, 4, 6 or 8. Number 346 — last digit 6, even — divisible. 573 — last digit 3, odd — not divisible.
Divisible by 5
Ends in 0 or 5. Number 145 — divisible. 328 — not divisible.
Divisible by 10
Ends in 0. 370 — yes. 375 — no. The simplest rule.
Divisible by 3
The digit sum is divisible by 3. 261: 2+6+1=9, 9÷3=3 — divisible. 274: 2+7+4=13 — not divisible by 3.
Divisible by 9
The digit sum is divisible by 9. 729: 7+2+9=18, 18÷9=2 — divisible. 534: 5+3+4=12 — not divisible by 9.
348 ÷ 2? (yes, ends in 8) · 345 ÷ 5? (yes, ends in 5)
252 ÷ 3? (2+5+2=9, yes) · 414 ÷ 9? (4+1+4=9, yes)
730 ÷ 10? (yes)
The "number sorter" game
A set of 15-20 numbers gets sorted into baskets: "divisible by 2," "by 3," "by 5," "by 9." A number can land in several baskets. All five rules reinforce together.
➗ Divisibility rests on division!
Our Pro mode trains division through groups of objects — the foundation every rule builds on.
🎮 Play