PEAZIT Aha card
Go straight to resources ↓Prime factorisation: stop only at prime factors
A prime has exactly two positive divisors: 1 and itself. Keep splitting composite factors until only primes remain.
| Expression | Meaning |
|---|---|
| 60 = 2 × 30 | Start with the smallest prime, 2. |
| 60 = 2 × 2 × 15 | 30 is still divisible by two. |
| 60 = 2² × 3 × 5 | Split 15 into 3 × 5; all factors are now prime. |
One worked example
- 60 = 2 × 30Start with the smallest prime, 2.
- 60 = 2 × 2 × 1530 is still divisible by two.
- 60 = 2² × 3 × 5Split 15 into 3 × 5; all factors are now prime.
Watch out: 1 is not a prime. The order of prime factors may change, but their counts must stay the same.
Goal, prerequisites and card origin
What you will learn: Write an integer greater than 1 as a product of primes.
What you need first: Divisibility and multiplication.
An original PEAZIT working card. Independent expert review and effectiveness testing have not yet taken place. · v1
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A prime has exactly two positive divisors: 1 and itself. Keep splitting composite factors until only primes remain.