18 of the best free LCM and HCF resources for KS3/4 maths

This KS3 maths worksheet is ideal for homework or classwork, and focuses on Highest Common Factor and Lowest Common Multiple. The objective is simply to be able to find the HCF and LCM of a pair of numbers.

The starter covers factors and multiples and some straightforward HCF and LCM questions, and the extension then looks at perfect numbers.

2 | HCF LCM Codebreaker

Figure out the answer to the (awful) joke by finding Highest Common Factor or Lowest Common Multiple of pairs of numbers.

Can be used for KS3/4 or even upper KS2.

3 | HCF LCM GCSE revision

This sheet covers prime factorisation and finding the HCF and LCM of two (or three) numbers, with exam-type questions that gradually increase in difficulty.

Note that these questions cover the full range of skills tested in GCSE and IGCSE for this topic and there are some problems solving questions at the end.

Detailed solutions are included, as is a new style of PowerPoint, which allows the questions and their solutions to be easily selected for enlarged display onto a screen, one at a time – this makes it easier (and quicker) to go through the solutions in class.

4 | Matching cards for KS3

This is a PowerPoint file with cards where students have to match a card with two numbers to a card with a highest common factor and lowest common multiple.

It’s a great revision tool for Highest Common Factors and Lowest Common Multiples.

5 | Spot the mistakes

Clive seems to have got a little confused on prime factors, HCF and LCM. His homework involves five questions, all of which he has got wrong. Can you help explain where he’s gone wrong?

This activity is designed to create mathematical discussion.

6 | Treasure hunt

This activity gives students practice at working out LCM or HCF of two numbers. A treasure hunt is a great activity which children love. They are ideal for revision, starters or plenaries. They are a really great way to get students to answer questions quickly and enjoy doing so.

Unlike most treasure hunts, this one has the added feature that the answers to the questions give an encrypted clue. When students decipher this clue, it reveals where the treasure is hidden!

The question cards have been prepared in two sizes. The large version can be pinned around the room and used for a whole class activity. The smaller cards can be used for group work or by individuals. The smaller cards are particularly helpful during interventions.

7 | HCF treasure hunt

Author: Simon Murphy

Students are given a pair of numbers and asked to find the highest common factor.

There are 10 questions in total.

Comes as an editable text document and as a PDF.

8 | Batman’s HCF LCM dilemma

Help Batman with his weaponry orders and tidying up the Batcave – can you help Batman arrange all his stuff?

9 | Prime factor decomposition

A KS3 PowerPoint showing prime factor decomposition and how to use this to find HCF and LCM.

10 | GCSE exam-style questions

This is a carefully selected compilation of questions on Highest Common Factor and Lowest Common Multiple. The full range of skills expected at GCSE are covered including finding the HCF and LCM of numbers presented as product of primes.

There are detailed fully-annotated solutions which can be made available to students to go through at home. This can free up considerable time in class.

11 | KS3 factors and HCF worksheet

A simple factor worksheet for Key Stage 3. The starter is three sets of division questions of various difficulties, and there’s an extension activity to get students looking at factors of square numbers.

12 | Phineas and Ferb HCF LCM activity

Five HCF and LCM functional questions using the characters from Phineas and Ferb. All put together in a PowerPoint and including answers. Now with a link to the Phineas and Ferb theme tune!

13 | Prime Decomposition HCF and LCM

Author: Owen134866

Calculate the HCF and LCM of two (or more) numbers by using prime decomposition and Venn diagrams.

14 | LCM Xmas party

Andy hates having waste, so calculate how many people he should invite to the party to ensure that he has no leftovers.

15 | Multiple choice HCF starter

A KS3 PowerPoint with 10 multiple-choice questions on highest common factors.

16 | Loop cards

This download contains four sets of cards. Students choose a set and sort them into order by answering the questions. Then they try to do it faster using a different set, which has a different sort order. The cards can either be used by individuals, pairs or small groups.

Solutions and instructions are included. Cut-out card size is approx 65 x 90 mm.