Factors & Primes
Rectangles, the prime hunt and frog jumps.
Learn with Kutty
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Factors are numbers that divide exactly into a number.
Look: All the ways to make 12 squares into a rectangle: 1 × 12, 2 × 6, 3 × 4.
✏️ Your turn!
Type your answer and press Check. Kutty will tell you if it is right.
1Factors of 18?
2Primes between 10 and 20?
3First five multiples of 7?
! Careful!
✗Thinking 1 is prime.
✓1 has only one factor, so it is not prime.
✗Thinking all odd numbers are prime.
✓9 = 3 × 3 is odd but not prime.
See the whole lesson on one page
Factors are numbers that divide exactly into a number.
Factors come in pairs: 3 × 4 = 12. A prime number has only two factors: 1 and itself, like 2, 3, 5, 7. 1 is not prime.
Think of it like this12 chairs can go in rows of 1, 2, 3, 4, 6 or 12 with none left over. Those are the factors of 12.
- Factor
- Divides in exactly.
- Prime
- Only 1 and itself.
- Multiple
- In its times table: 7, 14, 21…
Solved together
What are the factors of 36?
Find pairs that make 36, starting from 1.
1 × 362 × 183 × 124 × 96 × 65 does not work. After 6 × 6 the pairs repeat, so stop.
Answer1, 2, 3, 4, 6, 9, 12, 18, 36.
Now practise it
Kanakku makes new questions on factors & primes every time. It shows the working and gives a hint when you are stuck.