Factor pairs of 24
1 x 24, 2 x 12, 3 x 8 and 4 x 6 all make 24.
Stop when the pairs begin to repeat.
Year 5
Identify multiples and factors, including finding all factor pairs of a number, and common factors of two numbers
Recognise multiples and factors, list factor pairs, and find common factors of two numbers.
Lesson overview
Number - multiplication and division
A factor divides exactly into a number. A multiple is found by multiplying a number by a whole number. Factor pairs come in matching pairs, and common factors are factors shared by two numbers.
Multiples follow a pattern
The multiples of 6 are 6, 12, 18, 24, 30 ...
Each multiple is another group of the same size.
Common factors
The common factors of 12 and 18 are 1, 2, 3 and 6.
1, 2, 3, 4, 6, 12
1, 2, 3, 6, 9, 18
Look for the factors that appear in both lists.
Worked example
Find all factor pairs of 36.
start at 1
test 2
test 3, 4, 6
- Start with 1 x 36.
- Check 2, 3, 4 and 6 in turn.
- The pairs are 1 and 36, 2 and 18, 3 and 12, 4 and 9, 6 and 6.
- Stop once the factors begin to repeat.
Round 1: Learn it
List factors carefully and look for exact division.
Finish this round to unlock Round 2: Show you know it.
Question 1
Which number is a factor of 24?
Question 2
Which list shows multiples of 8?
Question 3
How many factor pairs does 16 have?
Question 4
Which is a common factor of 12 and 18?
1, 2, 3, 4, 6, 12
1, 2, 3, 6, 9, 18
Question 5
Which pair is a factor pair of 30?
Common mistakes
Watch for these as you work through the lesson.
- Mixing up factors and multiples.
- Missing a factor pair in the middle of the list.
- Including numbers that do not divide exactly.
Related topics
These ideas connect closely to this lesson.
- Know and use the vocabulary of prime numbers, prime factors and composite numbers.
- Solve problems involving multiplication and division, including scaling and correspondence problems.