Myths about teaching can hold you back
- Year 7
Lowest common multiple
I can use the prime factorisation of two or more positive integers to efficiently find their lowest common multiple.
- Year 7
Lowest common multiple
I can use the prime factorisation of two or more positive integers to efficiently find their lowest common multiple.
Lesson details
Key learning points
- 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
Keywords
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.
Common misconception
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.
To help you plan your year 7 maths lesson on: Lowest common multiple, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 7 maths lesson on: Lowest common multiple, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 3 maths lessons from the Properties of number: factors, multiples, squares and cubes unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Complete the statement. A number that is a multiple of two or more numbers is called a multiple.
Q2.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
Q3.Which of the following is a factor of $$2^3\times3^4\times5^2$$ and of $$2^3\times3^5\times5$$?
Q4.Select the correct statements.
Q5.The HCF of 84, 180 and 120 is .
Q6.The HCF of 126, 945 and 189 is 63. The missing prime factor in the Venn diagram is .
Assessment exit quiz
6 Questions
Q1.What does the L stand for in LCM?
Q2.Which of the following is not a multiple of $$2\times3^2\times5$$?
Q3.Given that $$12 = 2^2\times3$$, write 60 as a product of its prime factors.
Q4.The LCM of 18 and 30 is
Q5.The LCM of 70 and 42 is 210. So, the missing prime factor in the Venn diagram is
Q6.The LCM of 12, 20 and 84 is
