# /8/08 GCF, LCM Using Prime Factors #19

## Presentation on theme: "/8/08 GCF, LCM Using Prime Factors #19"— Presentation transcript:

40 56 18 36 54 10/8/08 GCF, LCM Using Prime Factors #19
Add the above heading to graph paper and your table of contents, then find the prime factorization of each number below. Today’s Plan: Warm-up and review Practice! Assignment: #1-14 all on graph paper showing all work including factor tree and prime factorization line up. Reminders: Use pencil! Quiz tomorrow

Using Prime Factorization to Find the GCF and LCM
Write the prime factorization of each number and circle the common factors. 40 = 2 · 2 · 2 · 5 56 = 2 · 2 · 2 · 7 2 · 2 · 2 = 8 Multiply the common prime factors. The GFC is 8. 2 · 2 · 2 · 5 · 7 8 · 5 · 7 40 · 7 The LCM is 280.

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Find the GCF and LCM B. 18, 36, 54 18 = 2 · 3 · 3 36 = 2 · 2 · 3 · 3 54 = 2 · 3 · 3 · 3 2, 3, 3 2 · 3 · 3 6 · 3 18 18 · 2 · 3 36 · 3 The LCM is 108. The GCF is 18.

Using Prime Factorization to Find the GCF
Course 2 2-5 Greatest Common Factor Using Prime Factorization to Find the GCF Find the greatest common factor (GCF). B. 252, 180, 96, 60 Write the prime factorization of each number and circle the common prime factors. 252 = 2 · 2 · 3 · 3 · 7 180 = 2 · 2 · 3 · 3 · 5 96 = 2 · 2 · 2 · 2 · 2 · 3 60 = 2 · 2 · 3 · 5 2 · 2 · 3 = 12 Multiply the common prime factors. The GCF is 12.

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Course 2 2-5 Greatest Common Factor Insert Lesson Title Here Find the greatest common factor (GCF). A. 72, 84 72 = 2 · 2 · 2 · 9 Write the prime factorization of each number and circle the common factors. 84 = 2 · 2 · 7 · 3 2 · 2 = 4 Multiply the common prime factors. The GCF is 4.

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Course 2 2-5 Greatest Common Factor Insert Lesson Title Here Find the greatest common factor (GCF). B. 360, 250, 170, 40 360 = 2 · 2 · 2 · 9 · 5 Write the prime factorization of each number and circle the common prime factors. 250 = 2 · 5 · 5 · 5 170 = 2 · 5 · 17 40 = 2 · 2 · 2 · 5 Multiply the common prime factors. 2 · 5 = 10 The GCF is 10.

Using Prime Factorization to Find the LCM
Course 2 2-6 Least Common Multiple Using Prime Factorization to Find the LCM Find the least common multiple (LCM). B. 14, 35, 49 14 = 2 · 7 Write the prime factorization of each number. 35 = 5 · 7 Circle the common prime factors. 49 = 7 · 7 List the prime factors, using the circled factors only once. 2, 5, 7, 7 2 · 5 · 7 · 7 Multiply the factors in the list. The LCM is 490.

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Course 2 2-6 Least Common Multiple Insert Lesson Title Here Find the least common multiple (LCM). A. 50, 130 50 = 2 · 5 · 5 Write the prime factorization of each number. 110 = 2 · 5 · 11 Circle the common prime factors. List the prime factors, using the circled factors only once. 2, 5, 5, 11 2 · 5 · 5 · 11 Multiply the factors in the list. The LCM is 550.

Using Prime Factorization to Find the LCM
Course 2 2-6 Least Common Multiple Using Prime Factorization to Find the LCM Find the least common multiple (LCM). A. 60, 130 60 = 2 · 2 · 3 · 5 Write the prime factorization of each number. 130 = 2 · 5 · 13 Circle the common prime factors. 2, 2, 3, 5, 13 List the prime factors, using the circled factors only once. 2 · 2 · 3 · 5 · 13 Multiply the factors in the list. The LCM is 780.