1.2 Common multiples & factors
FINDING COMMON MULTIPLES
TASK 1
1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
b circle all the multiples of 8
21
22
23
24
25
26
27
28
29
30
Now list all the common multiples of
6 and 8.
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
On the hundred grid,
a
2
Use the 100 grid
colour all the multiples of 6
_________________________________
3
4
What is the lowest common multiple (LCM)
of 6 and 8? ____________
James and Harry had the same amount of
money. James spent all his money on books
that cost $6 each and Harry spent all his on
books costing $8 each.
If they both had more than $50 but less than $90, how many books did they each buy?
______________________________________________________________________________
______________________________________________________________________________
TASK 2
Use lists
Continue each list to find the first 12 multiples for each number.
1
1st
2nd
3rd
4th
5th
9:
9
18
27
36
45
12:
12
24
36
48
60
72
15:
15
30
45
60
75
90
2
3
4
6th
7th
8th
9th
10th
11th
12th
105
a
What are the first three common multiples of 9 and 12?
______________
b
Predict the next two common multiples of 9 and12 not shown in the table.
______________
a
What are the first two common multiples of 12 and 15?
______________
c
Predict the next two common multiples of 12 and15 not shown in the table. _______________
What is the LCM of 9, 12 and 15?
© 2023 Cambridge University Press
______________
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Chapter 1 Reviewing number concepts
1.2 Common multiples & factors
TASK 3
Explore common multiples
1
The first three common multiples of 36 and 42 are 252, 504 and 756. What are their next 3 common
multiples?
2
Without repeating a number, give three pairs of numbers that have a common multiple of 12.
3
The LCM of 5 and 20 is in fact 20. Write at least 3 other pairs of numbers where one of the
numbers is the LCM for the pair.
4
A game board has numbers on each space. Starting from space 1, Sam jumps 5 spaces each turn,
Bill jumps 6 spaces each turn and Anne jumps 8 spaces each turn. What is the first space that they
will all land on?
5
A pile of golf balls can be packed into boxes of 6, boxes of 10 or boxes of 14 with none left over.
What is the smallest possible number of golf balls in the pile? You might like to use a calculator.
© 2023 Cambridge University Press
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Chapter 1 Reviewing number concepts