Page 58 - Maths Class 05

144 2 0 4 1

– 1 4 4

0 6 0 1 4 4 2

– 1 2 0

2 4 6 0 2

– 4 8

1 2 2 4 2
The last divisor is 12. – 2 4

\ HCF = 12 0

Least Common Multiple (LCM)

The Least Common Multiple (LCM) of two numbers is the smallest number (not zero)

that is a multiple of both the numbers .

Multiples of 3 :

0 , 3, 6, 9, 12 , 15, 18, 21, 24 .........

Multiples of 4 :

0 , 4, 8, 12 , 16, 20, 24 , 28.........

The LCM of 3 and 4 is 12.

Let us find the LCM of 30 and 45.

One way to find the Least Common Multiple (LCM) of two numbers is to first list the
prime factors of each number.

30 = 2 × 3 × 5

45 = 3 × 3 × 5

Then, multiply each factor the greatest number of times it occurs in other number. If
the same factor occurs more than once in both the numbers, you multiply the factor
the greatest number of times it occurs.

2 : one occurrence

3 : two occurrences

5 : one occurrence

LCM = 2 × 3 × 3 × 5 = 90

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