LESSON 4 – MULTIPLES AND LEAST COMMON MULTIPLES
Objectives:
At the end of the lesson, students should be able to;
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List the multiples of any given number
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Identify and list the common multiples
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Pick out the smallest or least number or numbers from the list. This is the lowest common multiple.
The multiples of a number are those numbers into which that number divides evenly.
Examples 1
List the first 5 multiples of 7.
7 = {7, 14, 21, 28, 35}
List the first 5 multiples of 9
9 = {9, 18, 27, 36, 45}
List the first 5 multiples of 8
8 = {8, 16, 24, 32, 40}
List the first 5 multiples of 12
12={12, 24, 36, 48, 60}
Examples 2
Write down the common multiples of 3 and 4
First list at least the first 12 multiples of each number.
3 = {3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36}
4 = {4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48}
List all the common multiples.
Common multiples of 3 and 4 = {12, 24, 36}
Examples 3
Write down the common multiples of 5 and 10
5 and 10
5 = {5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60}
10 = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120}
CM = {10, 20, 30, 40, 50, 60}
Examples 4
Write down the common multiples of 3 and 9
3 and 9
3 = {3, 6, 9, 12, 15, 18, 21, 24, 24, 27, 30, 33, 36}
9 = {9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108}
CM = {9, 18, 27, 36}
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Write down the common multiples of 2, 4 and 8
2, 4 and 8
2 = {2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28}
4 = {4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48}
8 = {8, 16, 24, 32, 40, 48, 56, 64, 72, 72, 80, 88, 96}
C.M = {8, 16, 24}
Note: sometimes you may have to list multiples beyond the first 12.
Find the least common multiples of the following sets of numbers.
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3 and 6
3 = {3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36}
6 = {6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72}
CM = {6, 12, 18, 24, 30, 36}
LCM = {6}
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5 and 10
5 = {5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70}
10 = {10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120}
CM = {10, 20, 30, 40, 50, 60, 70}
LCM = {10}
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3 and 9
3 = {3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36}
9 = {{9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108}
CM = {9, 18, 27, 36}
LCM = {9}
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3, 6 and 9
3 = {3, 6, 9, 12, 15, 18, 21, 24, 27, 30, 33, 36}
6 = {6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72}
9 = {9, 18, 27, 36, 45, 54, 63, 72, 81, 90, 99, 108}
CM = {18, 36}
LCM = {18}
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4, 8 and 12