How Do You Find the Factors Between Two Numbers?

To find the factors between two numbers, compare the factors of each number. Any number that appears in both lists is a common factor.

For example, the common factors of 18 and 24 are:

1, 2, 3, and 6

Step-by-Step: Get Common Factors of 18 and 24

Step 1: Start with the smaller number

Between 18 and 24, the smaller number is 18.

Step 2: Find all factors of 18

  • Begin with 1 and 18 → List: 1, 18
  • 18 ÷ 2 = 9 → Add 2 and 9 → List: 1, 2, 9, 18
  • 18 ÷ 3 = 6 → Add 3 and 6 → List: 1, 2, 3, 6, 9, 18
  • 18 ÷ 4 = 4.5 → Not a factor
  • Stop at √18 ≈ 4.2

Final factors of 18:
1, 2, 3, 6, 9, 18

Step 3: Check which of these factors also divide into 24

FactorDivides 24?Common Factor?
1✅ Yes✅ Yes
2✅ Yes✅ Yes
3✅ Yes✅ Yes
6✅ Yes✅ Yes
9❌ No❌ No
18❌ No❌ No

✅ Final list of common factors:
1, 2, 3, 6

Summary

To find the common factors of two numbers:

  1. Start with the smaller number.
  2. List all of its factors.
  3. Check which of those numbers also divide into the larger number.
  4. The numbers that divide both without leaving a remainder are your common factors.

For 18 and 24, the common factors are:

1, 2, 3, and 6

Try the same method for common factors of 12 and 18 or common factors of 28 and 42.