What are prime factors?
In GCSE maths, prime factors are the prime numbers which multiply to give that number. For example, the prime factors of 12 are 2 and 3. This is because 12 can be written as 2×2×3. The prime factors of 30 would be 2, 3 and 5, as 30 can be written as 2×3×5.
The process of writing a number as a product of its prime factors is known as prime factor decomposition. Read our revision note about prime factor decomposition to find out more.
What is a prime number?
A prime number is a number which has exactly two factors, itself and 1. Remember that 1 is not a prime number, as it only has one factor. You should remember at least the first ten prime numbers: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29.
Prime factors revision resources to ace your exams
Learn more about types of numbers and prime factor decomposition with our revision notes. To test your knowledge, try our prime factors, HCF & LCM exam questions.
For quick-fire GCSE maths revision use our collection of interactive flashcards for GCSE maths. We also have past papers for your exam practice.
Need help reaching your target grade? Explore our notes, questions by topic and worked solutions, tailor-made for GCSE Maths.
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