NumIO math adventure

Factor and Multiple Village

The village gates open when numbers share the right factors and multiples.

Learning goal

Find factors, multiples, common factors, common multiples, GCF, and LCM.

Skills you will practise

  • Factors and multiples
  • Common factors and common multiples
  • Greatest common factor and least common multiple

Worked examples

Factors of 45: 1, 3, 5, 9, 15, 45

  1. A factor of 45 divides 45 exactly, with no remainder. Starting from 1, look for pairs of numbers whose product is 45.
  2. 1 × 45 = 45, 3 × 15 = 45 and 5 × 9 = 45. The numbers 2, 4, 6, 7 and 8 do not divide 45 exactly, so they are not factors.
  3. The next number to try is 9, but it already appears in the pair 5 × 9, so we can stop. The factors of 45 are 1, 3, 5, 9, 15 and 45: 6 factors in all.
  4. Factors and multiples describe the same relationship from two sides. Because 5 × 9 = 45, 5 and 9 are factors of 45, and 45 is a multiple of both 5 and 9.

GCF(42, 56) = 14

  1. List all the factors of 42: 1, 2, 3, 6, 7, 14, 21, 42.
  2. List all the factors of 56: 1, 2, 4, 7, 8, 14, 28, 56.
  3. The numbers in both lists are the common factors: 1, 2, 7, 14. The greatest of them, 14, is the greatest common factor.
  4. Check by dividing: 42 ÷ 14 = 3 and 56 ÷ 14 = 4. The quotients 3 and 4 share no factor other than 1, so there is no common factor greater than 14.

LCM(12, 18) = 36

  1. Write the multiples of the larger number, 18, in order: 18, 36, 54, 72.
  2. Look for the first one that is also a multiple of 12. 18 cannot be divided exactly by 12, but 36 ÷ 12 = 3, so 36 is a multiple of 12.
  3. So 36 is the smallest common multiple of 12 and 18. The common multiples 36, 72, 108, … are all multiples of the least common multiple 36.
  4. Check with the greatest common factor. The GCF of 12 and 18 is 6, and 12 = 6 × 2 and 18 = 6 × 3, so the LCM is 6 × 2 × 3 = 36.

Common mistake

Do not mix up factors and multiples. A factor divides the number exactly, so it is never larger than the number; a multiple is made by multiplying the number, so it is never smaller. Also, the least common multiple is not always the product of the two numbers: look for the first number that appears in both lists of multiples.

Teach-back question

How is a factor of a number different from a multiple of it? Why is every common multiple of two numbers a multiple of their least common multiple?

How to play

Read the short story, explore the visual model, and complete five untimed questions. Use the hint when you need a new way to think.

Classroom idea

Ask the learner to explain the model or strategy before choosing an answer, then celebrate a clear explanation as well as a correct result.

Frequently asked questions

What grade is “Factor and Multiple Village” for?

“Factor and Multiple Village” is a Grade 5 Math lesson in NumIO. It practises: factors and multiples, common factors and common multiples, greatest common factor and least common multiple.

How does the “Factor and Multiple Village” mission work?

Each mission has five untimed questions. If an answer is not right yet you can try again, and the hint button offers another way to think.

Is “Factor and Multiple Village” free, and do I need an account?

Yes, it is free and there is no account or sign-up. Progress is saved in this browser, so you can come back and continue the mission later.

Back to the adventure map

Elementary math curriculum

First discoveries

Level 1

  • Tens and Ones to 100 — Read two-digit numbers and see how tens and ones build each number.
  • Twenty-Step Addition — Add and subtract within twenty, including missing parts of an equation.
  • Compare and Complete — Compare numbers with words and signs, then complete a missing-number equation.
  • Shape and Place — Name familiar shapes and describe where objects are using position words.
  • Measure and Tell Time — Compare lengths, measure with a simple unit, and read an hour on a clock.
  • Patterns and Groups — Continue repeating patterns, sort objects by a feature, and read a small count.

Level 2

Level 3

Level 4

Level 5

Level 6