To write 1000 as product of prime factors using a factor tree:

First split 1000 into 50 × 20. 50 and 20 are not prime numbers so split both of these numbers up.

Next write 50 as 10 × 5 and write 20 as 5 × 4. Highlight the 5’s as 5 is a prime number, and split 10 and 4 up into factor pairs.

10 can be split up into 5 × 2, and 4 can be split into 2 × 2. Highlight all these numbers as 2 and 5 are prime numbers.

Therefore, 1000 written as a product of prime factors is:

2 × 2 × 2 × 5 × 5 × 5

You can also write this out using powers as:

2³ × 5³.

There are also other factor trees that you could use to write down 1000 as a product of prime factors. For example, at the start of the factor tree 1000 could be split into 10 × 100 or 5 × 200 instead of 50 × 20. However, you will always end up with the same answer if you have worked it out correctly.

Extra Help:

Writing down easier numbers as a product of prime factors.

Harder questions on the product of prime factors using factor trees.