6 — Factors and Prime Numbers

Factors and Prime Numbers

Solution & Explanation · ID: 504412E9

Question

List all factors of 20.

Hint

Remember to check factor pairs systematically.

Concept

Factors are numbers that divide evenly into another number. To find all factors, we test each number from 1 up to the given number to see which ones divide evenly.

Show Answer

1, 2, 4, 5, 10, 20

Show Solution
1

Start with 1: 20 ÷ 1 = 20 (no remainder), so 1 and 20 are factors.

2

Try 2: 20 ÷ 2 = 10 (no remainder), so 2 and 10 are factors.

3

Try 3: 20 ÷ 3 = 6.67... (has remainder), so 3 is not a factor.

4

Try 4: 20 ÷ 4 = 5 (no remainder), so 4 and 5 are factors.

5

We already found 5, and numbers beyond 5 would repeat pairs we've found.

A factor tree diagram showing 20 at the top. Below it are factor pairs connected by lines: (1,20), (2,10), and (4,5). Each pair is enclosed in a box. At the bottom, all factors are listed in order: 1, 2, 4, 5, 10, 20.