Understanding Factors and Greatest Common Factors

This video tutorial introduces the concept of factors in mathematics, using the rainbow method to find factors of numbers like 12. It explains how to calculate the greatest common factors (GCF) between two numbers, specifically 12 and 18, and demonstrates how to use the GCF to simplify fractions. The tutorial provides clear examples and step-by-step instructions to help viewers understand these mathematical concepts.

What is a factor in mathematics?

• A number that is a product of two other numbers

• A number that is the sum of two other numbers

• A number that is always greater than another number

• A number that divides another number without leaving a remainder

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CCSS.4.OA.B.4

Which of the following is NOT a factor of 12?

• 1

• 3

• 5

• 6

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CCSS.4.OA.B.4

What is the first step in the rainbow method for finding factors?

• Subtract 1 from the number

• Find the square root of the number

• List the number and 1 as factors

• Divide the number by 2

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CCSS.4.OA.B.4

Which pair of numbers is a factor pair of 12?

• 8 and 3

• 5 and 2

• 3 and 4

• 7 and 1

What is the greatest common factor of 12 and 18?

• 12

• 9

• 6

• 3

Which of the following is a common factor of both 12 and 18?

• 6

• 7

• 5

• 8

How can the greatest common factor be used in mathematics?

• To find the average of two numbers

• To simplify fractions

• To multiply two numbers

• To find the square root of a number

What is the simplified form of the fraction 12/18 using the greatest common factor?

• 1/2

• 3/2

• 2/3

• 4/6

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CCSS.4.OA.B.4

If the greatest common factor of two numbers is 1, what are these numbers called?

• Prime numbers

• Composite numbers

• Co-prime numbers

• Even numbers

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CCSS.3.NF.A.3A

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

Which of the following fractions is equivalent to 12/18?

• 4/6

• 2/3

• 3/4

• 5/6

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CCSS.3.NF.A.3A

CCSS.3.NF.A.3B

CCSS.4.NF.A.1