- Definition
A prime factor is a number that divides evenly into another number (a factor) and is also a prime number itself (meaning it can only be divided by 1 and itself).
To find the prime factors of 10, you break it into 2 × 5; since both 2 and 5 are prime, they are its prime factors.
How to teach this in 30 seconds
Try this analogy: Prime factors are like the most basic Lego bricks you use to build a number — they can't be broken down into smaller bricks.
Ask your child: If 12 is a Lego model, what are its unbreakable building blocks?
Common mix-up: Kids might think any factor counts, like saying 6 is a prime factor of 12. Prime factors are the special factors that are also prime numbers.
Examples
- The prime factors of 12 are 2 and 3, because 12 can be written as 2 × 2 × 3.
- The number 13 is a prime number, so its only prime factor is 13.
prime factor is a term used in Ontario’s Kindergarten to Grade 8 curriculum.
Where this shows up
The descriptions on this page are SmartStudy’s own original, plain-language writing — not the Ministry’s wording. They are aligned to the Ontario Curriculum, © King’s Printer for Ontario. For the Ministry’s official wording, see the source link below. SmartStudy is an independent service and is not affiliated with, endorsed by, or sponsored by the Government of Ontario or the Ministry of Education. Ontario Curriculum and Resources ↗
