Adding Fractions and LCM Concepts

This video tutorial explains how to add fractions using two methods. It begins with examples of adding two fractions by multiplying denominators and cross-multiplying numerators. The video then provides practice problems and introduces an alternative method using a common denominator, which is useful for adding multiple fractions. The tutorial concludes with examples of adding three fractions and emphasizes finding the least common multiple.

What is the first step in adding two fractions using the cross-multiplication method?

• Add the numerators directly

• Multiply the denominators

• Find a common denominator

• Subtract the numerators

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CCSS.5.NF.A.1

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In the example 2/3 + 3/4, what is the result of cross-multiplying the numerators?

• 6 and 9

• 8 and 9

• 6 and 8

• 9 and 8

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CCSS.5.NF.A.1

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What is the result of adding 5/3 and 1/2 using the cross-multiplication method?

• 13/6

• 11/6

• 15/6

• 17/6

What is the least common multiple of 5, 4, and 3?

• 30

• 40

• 60

• 50

In the alternative method, what is the common denominator for 3/8 and 5/7?

• 48

• 72

• 56

• 64

How do you find the least common multiple of 4, 6, and 2?

• List multiples and find the smallest common one

• Add all numbers together

• Find the highest number

• Multiply all numbers together

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CCSS.5.NF.A.1

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What is the sum of 2/5, 3/4, and 1/3 using the least common multiple method?

• 85/60

• 89/60

• 95/60

• 99/60

What is the least common multiple of 4, 6, and 2?

• 14

• 10

• 12

• 8

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CCSS.5.NF.A.1

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What is the result of adding 1/4, 5/6, and 1/2 using the least common multiple method?

• 17/12

• 19/12

• 20/12

• 18/12

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CCSS.5.NF.A.1

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What should you do if you want to add more than two fractions?

• Use the cross-multiplication method

• Find a common denominator for all fractions

• Add the numerators directly

• Subtract the smallest fraction

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2