The big picture
Every number has its own factor list.
| Idea | Remember | Example |
|---|---|---|
| Factors | Divides exactly, nothing left over. | 12 → 1, 2, 3, 4, 6, 12. |
| Multiples | Steps you count up — never stops. | 6 → 6, 12, 18, 24… |
| Primes | Exactly two factors: 1 and itself. | 7 → 1, 7. |
| Composites | More than two factors. | 9 → 1, 3, 9. |
| Divisibility | A quick test, no dividing needed. | 348 → 2 and 3 fit. |
| Common factors | Numbers on two factor lists at once. | 12 & 18 → 1, 2, 3, 6. |
Open Chapter 5, Prime Time, in your NCERT book. You have already met its main ideas here.