How Do You Find the Factors Between Two Numbers?
To find the factors between two numbers, compare the list of factors for each number. Any number that appears in both lists is called a common factor.
For example, the common factors of 12 and 18 are:
1, 2, 3, and 6
Get Common Factors of 12 and 18
Here’s how to find common factors using a step-by-step approach.
Step-by-Step Table
| Find Common Factors of 12 and 18 |
|---|
| Start with the smaller number: 12 |
| List all factors of 12 |
| - Begin with 1 and 12 → List: 1, 12 |
| - 12 ÷ 2 = 6 → Add 2 and 6 → List: 1, 2, 6, 12 |
| - 12 ÷ 3 = 4 → Add 3 and 4 → List: 1, 2, 3, 4, 6, 12 |
| - Stop: You’ve reached √12 |
So, the factors of 12 are:
1, 2, 3, 4, 6, 12
Check Which Factors Also Divide 18
| Factor | Divides 18? | Add to Common List? |
|---|---|---|
| 1 | Yes | ✅ |
| 2 | Yes | ✅ |
| 3 | Yes | ✅ |
| 4 | No (remainder 2) | ❌ |
| 6 | Yes | ✅ |
| 12 | No (remainder 6) | ❌ |
✅ Final list of common factors:
1, 2, 3, 6
Summary
To find the common factors of two numbers:
- List all the factors of the smaller number.
- Check which of these also divide into the larger number with no remainder.
- The numbers that meet both conditions are the common factors.
For 12 and 18, the common factors are:
1, 2, 3, 6
Try it yourself!
Find the common factors of 18 and 24 or the common factors of 28 and 42.