Applying GCF and LCM in Fraction Operations

This video tutorial covers the application of the greatest common factor (GCF) and least common multiple (LCM) in operations involving fractions. It explains how to multiply fractions by multiplying numerators and denominators directly and introduces the cross-cancelling method to simplify the process. The tutorial also covers addition and subtraction of fractions, emphasizing the need for common denominators. The video concludes with practice problems to reinforce the concepts taught.

What is the goal of the lesson in terms of accuracy?

• 80% accuracy

• 100% accuracy

• 70% accuracy

• 90% accuracy

Tags

CCSS.5.NF.B.6

When multiplying fractions, what is the first step?

• Subtract the denominators

• Multiply straight across

• Find a common denominator

• Add the numerators

Tags

CCSS.5.NF.B.6

What is the result of multiplying 3/8 by 1/4?

• 3/32

• 1/12

• 3/12

• 1/32

Tags

CCSS.5.NF.B.6

What is cross-cancelling used for in multiplication of fractions?

• To add fractions

• To subtract fractions

• To find a common denominator

• To simplify fractions before multiplying

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Which operation should not use cross-cancelling?

• Multiplication

• Addition

• Subtraction

• Both Addition and Subtraction

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D

Why must fractions have the same denominator for addition and subtraction?

• To make multiplication easier

• To find the greatest common factor

• To simplify the fractions

• To ensure equal parts are being added or subtracted

What is the least common multiple (LCM) of 4 and 8?

• 4

• 8

• 12

• 16

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the result of adding 1/6 and 4/12?

• 1/3

• 5/12

• 2/3

• 1/2

What is the least common multiple (LCM) of 7 and 21?

• 14

• 28

• 7

• 21

Tags

CCSS.7.NS.A.1C

What is the result of subtracting 1/21 from 3/7?

• 3/21

• 1/7

• 8/21

• 2/21

Tags

CCSS.7.NS.A.1C