Finding prime factors
primeA number that only has two factors - itself and one. factors are factorA factor is a number which divides exactly into another number. 1 is a factor of every number and every number is a factor of itself. A number can have several factors. Example: 1, 2, 5 and 10 are the factors of 10. of a number that are, themselves, prime numbers.
Sometimes you might be asked to write a number as the productThe answer when two or more numbers are multiplied together, eg the product of 4 and 15 is 60. of its prime factors.
There are many methods to find the prime factors of a number, but one of the most common is to use a prime factor tree:
- Start the factor tree using any pair of factors (two numbers that multiply together to make your number).
- If one of these factors is prime, that branch ends.
- If a factor isn't prime, divide it into a factor pair.
- The branches continue to expand until all the factors are prime numbers.
- The final answer is the list of all the prime numbers displayed at the end of these branches.
Example:
Write 24 as the product of its prime factors.
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