Chapter 7.3 Least Common Multiple and Greatest Common Factor

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Chapter 7.3Least Common Multiple and Greatest
Common Factor

• MATRIX Grant Project
• Tatiana
• Jenny
• 607

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Directions

• To find LMC you have to list all of the multiples
  of the numbers and find the smallest number that
  they both have.
• Another way to find the LCM is to write the prime
  factorizations then write a multiplication
  problem using all prime factors once. Then for
  each factor write the greatest exponent used with
  that factor in any of the prime factorizations.
  Last multiply.
• How to find the GFC list all the factors of each
  number find the common factors and then find the
  greatest common factors.

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Examples

• How To Find The LCM
• 66 12 18 24 30 36 42 48 54 60 66
  72
• 33 6 9 12 15 18 21 24 27 30 33 36
  39
• 99 18 27 36 45 54 63 72 81 90 99
  108
• The LCM For 6,3,and 9 is 18
• Another way to find the LCM is
• 6 12 18
  62x3
• / \ / \ / \
  122x2x3
• 2 3 2 6 3 6
  182x3x3
• / \ / \
  its 2x3
• 2 3 2 3
• How to find the GFC
• 81 2 4 8
• 121 2 3 4 6 12 The common factors are
  1,2,4 The GCF of 8 and 12 is 4

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Problems to solve
List the first 7 multiples Find the LCM of the 2 numbers Find the GFC of the 2 numbers
1) 12 2) 4 3) 5 4) 14 5) 18 6) 9 6) 10,20 7) 9,7 8) 12,18 9) 15,30 10) 5,6 11) 3,9 12) 21,7 13) 48,72 14) 12,36 15) 6,18
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http//www.toonuniversity.com/flash.asp?err499en
gine14

• In this game 2 numbers are going to appear on the
  screen. You are supposed to find the LCM and GFC
  for both numbers
• Just like the examples