1. HCF & LCM – Prime Factorisation – Messenger!
In this competitive activity, one student at a time acts as a messenger for their team of 2 or more students. Without running (!), they relay information about questions
(posted around the room) to their teammates who then answer them.
Students need to record the question letter and the answer so they can mark their work using the answer slide at the end of the activity. With the points system, students can attempt appropriate questions.
You could choose posters/questions to include and delete others.
(Clear plastic wallets around your classroom
make it quick and easy to display posters.)

2. Printing To print handouts from slides -
Select the slide from the left. Then click:
File > Print > ‘Print Current Slide’
To print multiple slides -
Click on a section title to highlight all those slides,
or press ‘Ctrl’ at the same time as selecting slides to
highlight more than one. Then click:
File > Print > ‘Print Selection’

3. Messenger!
Title Slide

4. 10 In teams pick a messenger! It’s their job to collect questions
for the rest of the team to answer.
You can change who is the messenger but
only one person is allowed to stand up at once and
they can’t carry a pen or paper to the question!
Each question is worth a different number of points!
Record the question letter and your
answer on a single piece of paper.
After marking,
the team that scores the most points wins! 10
Optional rules slide to show the class.

5. 45 120 4 3 Question B Question A Find the prime factors of:

6. 72 900 4 3 Question D Question C Find the prime factors of:

7. 22 × 3 × 5 22 × 3 × 52 3 3 Question F Question E What number is this
the prime factorisation for?
What number is this
the prime factorisation for?
22 × 3 × 5
22 × 3 × 52

8. Question G
Question H 4 4
What are the two numbers shown
in this Venn diagram?
What are the two numbers shown
in this Venn diagram? 2 2 2 3 3 5 3 2 2 3 5

9. Question I
Question J 5 6
What are the two numbers shown
in this Venn diagram?
What are the two numbers shown
in this Venn diagram? 5 2 2 5 2 3 3 3 2 5 2
What is the Highest Common Factor
and Lowest Common Multiple
of the numbers?
What is the Highest Common Factor
and Lowest Common Multiple
of the numbers?

10. 40 & 90 60 & 150 6 6 Question L Question K Find the
Highest Common Factor of
Find the
Highest Common Factor of
40 & 90
60 & 150

11. 24 & 40 250 & 75 7 7 Question N Question M Find the
Lowest Common Multiple of
Find the
Lowest Common Multiple of
24 & 40
250 & 75

12. 150 & 90 12 & 45 8 8 Question P Question O Find the HCF and LCM of

13. 8 7 Question Q Question R 3 2 2 3 5 The HCF of A and B is 12.
Complete the overlapping part
of the Venn diagram.
The HCF of A and B is 50.
Complete the overlapping part
of the Venn diagram. A B A B 3 2 2 3 5
What numbers are A and B?
What numbers are A and B?

14. 9 9 Question T Question S 2 5 2 3 2 3 The LCM of A and B is 540.
Complete the overlapping part
of the Venn diagram.
The LCM of A and B is 720.
Complete the overlapping part
of the Venn diagram. A B A B 2 5 2 3 2 3
What numbers are A and B?
What numbers are A and B?

15. 9 9 Question V Question U Two numbers have a
HCF of 10 and an LCM of 150.
Neither of the numbers is 10 or 150.
What are the numbers?
Two numbers – both lower than 30 –
have a HCF of 6 and an LCM of 72.
What are the numbers?

16. 10 10 Question X Question W Two numbers have a
HCF of 30 and an LCM of 180.
Both numbers are greater than 50.
What are the numbers?
Two numbers have a
HCF of 35 and an LCM of 1050.
Both numbers are smaller than 300.
What are the numbers?

17. 12 11 Question Z Question Y Copy the diagram and use it to
find the HCF and LCM of
27, 126 & 180.
Write the LCM in
prime factorisation form
with indices.
Copy the diagram and use it to
find the HCF and LCM of
30, 60 & 225.

18. N O P Q R S T U V W X Y Z A B C D E F G H I J K L M 3 7 4 8 9 5 10 6
Qu.
Answer
Points A
32 x 5 3 B
23 x 3 x 5 4 C
2 x 62 D
22 x 32 x 52 E 60 F
300 G
20 & 45 H
120 & 90 I
40 & 24:
HCF = 8, LCM = 120 5 J
90 & 300:
HCF = 30, LCM = 900 6 K
HCF = 10 L
HCF = 30 M
LCM = 120 7
Qu.
Answer
Points N
LCM = 750 7 O
HCF = 30, LCM = 450 8 P
HCF = 3, LCM = 180 Q
36 & 24 R
500 & 150 S
A = 108, B = 90 9 T
A = 180, B = 240 U
30 & 50 V
24 & 18 W
90 & 60 10 X
210 & 175 Y
HCF = 15, LCM = 900 11 Z
HCF = 9, LCM = 22 x 33 x 5 x 7 12
Answers to display so students can mark their own or another team’s work.

19. Answers to display so students can mark their own or another team’s work.

21. tom@goteachmaths.co.uk Questions? Comments? Suggestions?
…or have you found a mistake!?
Any feedback would be appreciated .
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