Lowest common multiple | Maths | Quizalize & Oak National Academy

Starter quiz

Complete the statement. A number that is a multiple of two or more numbers is called a ______ multiple.
- 'common' ✓
Match each number with its first four multiples.
- First four multiples of 2:
  
  ⇔
  
  2, 4, 6, 8 ✓
- First four multiples of 4:
  
  ⇔
  
  4, 8, 12, 16 ✓
- First four multiples of 3:
  
  ⇔
  
  3, 6, 9, 12 ✓
- First four multiples of 12:
  
  ⇔
  
  12, 24, 36, 48 ✓
Which of the following is a factor of $2^3\times3^4\times5^2$ and of $2^3\times3^5\times5$ ?
- $2^3\times3^5\times5^2$
- $2^2\times3^4\times5$ ✓
- $2^2\times3^4\times5$ ✓
- $2^3\times3^4\times5^2$
Select the correct statements.
- 240 as a product of prime factors is $2^4 \times 3 \times 5$ ✓
- 240 as a product of prime factors is $2^2 \times 3^2 \times 5$
- 180 as a product of prime factors is $2^2 \times 3 \times 5$
- 180 as a product of prime factors is $2^2 \times 3^2 \times 5$ ✓
The HCF of 84, 180 and 120 is ______.
- '12' ✓
The HCF of 126, 945 and 189 is 63. The missing prime factor in the Venn diagram is ______.
- '7' ✓

What does the L stand for in LCM?
- 'lowest' ✓
Which of the following is not a multiple of $2\times3^2\times5$ ?
- $2^2\times3^2\times5$
- $2^2\times3^3\times5$
- $2^2\times3\times5$ ✓
- $2^2\times3^2\times5^3$
Given that $12 = 2^2\times3$ , write 60 as a product of its prime factors.
- $2^3\times3$
- $2^2\times3\times12$
- $2^2\times3^2\times5$
- $2^2\times3\times5$ ✓
The LCM of 18 and 30 is ______
- '90' ✓
The LCM of 70 and 42 is 210. So, the missing prime factor in the Venn diagram is ______
- '7' ✓
The LCM of 12, 20 and 84 is ______
- '420' ✓

Loading worksheet ...

Loading presentation ...

Common multiples can be found using the prime factorisation of numbers
The lowest common multiple of two numbers can be found by comparing the prime factorisation of both numbers
Sometimes a Venn diagram can help identify the lowest common multiple of two numbers
The lowest common multiple of more than two numbers can be found using prime factorisation

When using a Venn diagram misplacement of factors is common.

Encourage students to check that the product of factors in each set is the correct integer.

Lowest common multiple - The lowest common multiple is the lowest number that is a multiple of two or more integers.
Lcm - LCM is an abbreviation for lowest common multiple.