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Daily Math Minute

Operations & Algebraic Thinking

Factors & Multiples

Finding factor pairs and recognizing multiples of a number.

Intermediate15 min lesson3 min readUpdated August 12, 2026Author not yet attributed

Factors and Multiples

Every whole number has a special relationship with the numbers that divide evenly into it, and with the numbers it divides evenly into. Factors and multiples describe those two related but different relationships.

Definition — Factor and Multiple

A factor of a number divides evenly into it with no remainder. A multiple of a number is the result of multiplying it by a whole number. 4 is a factor of 12 because 12 ÷ 4 has no remainder; 12 is a multiple of 4 because 4 × 3 = 12.

To find all the factor pairs of a number, test each whole number starting from 1, checking whether it divides evenly. To list multiples of a number, multiply it by 1, 2, 3, and so on — multiples of a number never stop, since there's no largest whole number to multiply by.

Worked Example — Finding All Factor Pairs

Find every factor pair of 18. Testing each number: 1 × 18 = 18, 2 × 9 = 18, 3 × 6 = 18. Testing 4 and 5 doesn't divide evenly. The factor pairs are (1, 18), (2, 9), and (3, 6), giving the factors 1, 2, 3, 6, 9, and 18.

Worked Example — Listing the First Several Multiples

List the first five multiples of 7. Multiply 7 by 1, 2, 3, 4, and 5: 7, 14, 21, 28, 35. Those are the first five multiples of 7.

Tip

A useful check: every number is both a factor and a multiple of itself, and 1 is a factor of every whole number, so factor lists always include both 1 and the number itself.

Common Mistakes

  • Confusing factors and multiples, such as calling 12 a factor of 4 instead of a multiple of 4.

    Factors are smaller than or equal to the original number and divide into it evenly; multiples are the same size or larger, produced by multiplying the number.

  • Stopping the search for factor pairs too early, missing pairs where both numbers are close together, like forgetting 3 × 6 = 18 while only checking 1 × 18 and 2 × 9.

    Test every whole number in order starting from 1, and stop only once the two numbers in a pair start repeating the pairs already found in reverse order.

Key Takeaways

  • A factor of a number divides evenly into it with no remainder.
  • A multiple of a number is the result of multiplying it by a whole number, and multiples never stop.
  • Testing whole numbers in order from 1 finds every factor pair of a number.

Summary

Factors and multiples describe how whole numbers relate to each other through multiplication and division. The next lesson uses a similar kind of structured thinking to generate and describe number patterns.