Least Common Multiple

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Least Common Multiple

• 4.4

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Multiples of 4 and 64 4, 8, 12, 16, 20, 24
6 6, 12, 18, 24, 30, 36
A multiple of a number is a product of that
number and a whole number
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4 4, 8, 12, 16, 20, 24 6 6, 12, 18,
24, 30, 36
Common Multiples
Least Common Multiple 4 4, 8, 12, 16, 20, 24
6 6, 12, 18, 24, 30, 36 (LCM) 12
4
(No Transcript)
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10 2 x 5 2 x 5
Use prime factorization (factor trees) to find
the LCM
Find the LCM of 10 and 24
Step 1 Find the prime factorization of each
number (write with exponents!)
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24 2 x 2 x 2 x 3 2 x 3
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The different prime factors are 2,3, and 5.
Step 2 Identify all the different prime factors
from both numbers
10 2 x 524 2 x 3
3
7
Step 3 Pick out the factor with the greatest
exponent10 2 x 524 2 x 3
3
8
Step 4 Multiply the prime factors with the
greatest power together
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2 x 3 x 5 120
LCM 120
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? Your Turn ? Find the LCM of 16 and 18
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16 2 x 2 x 2 x 2 2 18 2 x 3 x 3 2 x 3

Step 1 Prime Factorization
4
2
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Step 2 I.D. prime factors16 2 18 2 x 3
prime factors 2,3
4
2
12
Step 3 greatest exponent16 2 18 2 x 3
4
2
13
Step 4 Multiply2 x 3 144LCM 144
2
4
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? Your Turn ? Find the LCM of 4 and 15
60
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Find the LCM for 18, 24, and 48
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18 2 x 3 x 3 2 x 324 2 x 2 x 2 x 3 2 x
348 2 x 2 x 2 x 2 x 3 2 x 3
3
4
prime factors 2, 32 x 3 144 LCM
4
2
16
THOUGHT OF THE DAY!!

• The cruise liner, QE2, moves only six inches for
  each gallon of diesel that it burns.