Divisibility Rule for 3
✅ A number is divisible by 3 if the sum of its digits is divisible by 3.
Examples:
| Number | Sum of Digits | Divisible by 3? | Reason |
|---|---|---|---|
| 123 | 1 + 2 + 3 = 6 | ✅ Yes | 6 is divisible by 3 |
| 345 | 3 + 4 + 5 = 12 | ✅ Yes | 12 is divisible by 3 |
| 127 | 1 + 2 + 7 = 10 | ❌ No | 10 is not divisible by 3 |
| 81 | 8 + 1 = 9 | ✅ Yes | 9 is divisible by 3 |
| 100 | 1 + 0 + 0 = 1 | ❌ No | 1 is not divisible by 3 |