2 and 3
Multiples of 2:
2, 4, 6, 8, 10, 14, 16, 18, 20, 22, 24, 26, 28, 30, …
Multiples of 3:
3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, …
First 5 common multiples of 2 and 3 are: 6, 12, 18, 24, and 30.
(b) 5 and 8
Solution:
5 and 8
Multiples of 5:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195, 200, …
Multiples of 8:
8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, 136, 144, 152, 160, 168, 176, 184, 192, 200, …
First 5 common multiples of 5 and 8 are: 40, 80, 120, 160, and 200.
(c) 2 and 4
Solution:
Multiples of 2:
2, 4, 6, 8, 10, 12, 14, 16, 18, 20, …
Multiples of 4:
4, 8, 12, 16, 20, 24, 28, 32, …
First 5 common multiples of 2 and 4 are:
4, 8, 12, 16, and 20.
(d) 3 and 9
Solution:
Multiples of 3:
3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45, …….
Multiples of 9:
9, 18, 27, 36, 45, 54 …
First 5 common multiples of 3 and 9 are:
9, 18, 27, 36, and 45.
(e) 5 and 10
Solution:
Multiples of 5:
5, 10, 15, 20, 25, 30, 35, 40, 45, 50, …
Multiples of 10:
10, 20, 30, 40, 50, 60, 70, 80, 90, 100, …
First 5 common multiples of 5 and 10 are:
10, 20, 30, 40, and 50.
(f) 9 and 12
Solution:
Multiples of 9:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108, 117, 126, 135, 144, 153, 162, 171, 180, 189, …
Multiples of 12:
12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 132, 144, 156, 168, 180, 192, …
First 5 common multiples of 9 and 12 are: 36, 72, 108, 144, and 180.
(g) 8 and 12
Solution:
Multiples of 8:
8, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, …
Multiples of 12:
12, 24, 36, 48, 60, 72, 84, 96, 108, 120, ………..
First 5 common multiples of 8 and 12 are:
24, 48, 72, 96, and 120.
(h) 6 and 8
Solution:
Multiples of 6:
6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102, 108, 114, 120, 126, …
Multiples of 8:
8,16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 120, 128, …
First 5 common multiples of 6 and 8 are: 24, 48, 72, 96 and 120.
(i) 6 and 9
Solution:
Multiples of 6:
6, 12, 18, 24, 30, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, …
Multiples of 9:
9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, …
First 5 common multiples of 6 and 9 are: 18, 36, 54, 72 and 90.
What do you notice about the common multiples of different pairs of numbers? Discuss in class.
Solution:
Do it yourself.