PEAZIT Aha card
Go straight to resources ↓Divisibility: decide without long division
For 2, 5 and 10, inspect the last digit; for 3 and 9, use the digit sum. Match the rule to the divisor.
| Expression | Meaning |
|---|---|
| 234 → 4 | An even last digit means divisibility by 2. |
| 2 + 3 + 4 = 9 | The sum is divisible by 3 and 9. |
| 5: 0, 5; 10: 0 | For 5, the number ends in 0 or 5; for 10, only in 0. |
One worked example
- 234 → 4An even last digit means divisibility by 2.
- 2 + 3 + 4 = 9The sum is divisible by 3 and 9.
- 5: 0, 5; 10: 0For 5, the number ends in 0 or 5; for 10, only in 0.
Watch out: Divisibility by 3 does not imply divisibility by 9. For 6, the number must be divisible by both 2 and 3.
Goal, prerequisites and card origin
What you will learn: Check divisibility by 2, 3, 5, 9 and 10.
What you need first: Digits and division without remainder.
An original PEAZIT working card. Independent expert review and effectiveness testing have not yet taken place. · v1
Show connections
For 2, 5 and 10, inspect the last digit; for 3 and 9, use the digit sum. Match the rule to the divisor.