Topic 4-2 GCF, LCM and Prime Factorization

Topic 4-2 GCF, LCM & Prime Factorization

School Year 2022-2023​

​Essential Question

• ​How do you find the greatest common factor (GCF) and least common multiple (LCM) of two or more numbers?

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• ​But, first, some review questions...

Multiple Choice

1.) Which value is equivalent to the expression 4⁵?

• 9

• 20

• 625

• 1024

Multiple Select

2.) Select all the expressions equal to $$4^3$$  .

• 12

• 64

• 4 x 3

• 4 x 4 x 4

• (4 x 4) x 4

​Topic Agenda

• ​Learn about Greatest Common Factor (GCF)

• ​Learn about Least Common Multiple (LCM)

• Learn about Prime Factorization​

​What is the GCF?

​Factors that are shared by two or more numbers are called common factors. The greatest of the common factors is called the greatest common factor (GCF). One way to find the GCF of two or more numbers is by listing factors.

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3.) What is the GCF of 16 and 18?

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4.) What is the GCF of 28 and 49?

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5.) What is the GCF of 60 and 72?

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6.) What is the LCM of 4 and 6?

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7.) What is the LCM of 9 and 12?

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8.) What is the LCM of 15 and 25?

Multiple Choice

A composite number ...

• has more than 2 factors.
• has one factor.
• has at least 10 factors.
• is always a really big number.

Multiple Choice

A prime number...

• has one factor.
• has more than 2 factors.
• has 100 factors.
• has exactly 2 factors: 1 and the itself.

Multiple Choice

9.) Find the prime factorization of 100 in exponential form.

• 10 × 10

• 5⁴

• 4 x 25

• 2² × 5²

Multiple Choice

10.) Find the prime factorization of 75 in exponential form.

• 3 × 5²
• 3² × 5
• 5 × 15
• 3² × 5²