Finding Least Common Multiples and Fraction Conversions

The video tutorial explains how to add and subtract fractions with different denominators by finding the least common multiple (LCM). It demonstrates the process of converting fractions to have a common denominator and solving the problem step-by-step. A second example is provided for further practice.

Why is it necessary to find a common denominator when adding or subtracting fractions?

• To ensure the fractions have the same base for accurate addition or subtraction

• To convert fractions to whole numbers

• To simplify the fractions

• To make the numerators equal

What is the least common multiple (LCM) of 4, 5, and 10?

• 25

• 20

• 15

• 10

Tags

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

How do you convert 1/4 to a fraction with a denominator of 20?

• Multiply the numerator by 5 and the denominator by 4

• Multiply both the numerator and denominator by 5

• Multiply the numerator by 4 and the denominator by 5

• Multiply both the numerator and denominator by 4

Tags

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

What is 3/5 converted to a fraction with a denominator of 20?

• 15/20

• 6/20

• 12/20

• 9/20

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D

What is the result of 5/20 + 12/20 - 6/20?

• 12/20

• 10/20

• 13/20

• 11/20

What is the least common multiple (LCM) of 9, 6, and 3?

• 18

• 15

• 12

• 9

Tags

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

How do you convert 4/9 to a fraction with a denominator of 18?

• Multiply the numerator by 3 and the denominator by 2

• Multiply both the numerator and denominator by 2

• Multiply the numerator by 2 and the denominator by 3

• Multiply both the numerator and denominator by 3

Tags

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

What is 1/6 converted to a fraction with a denominator of 18?

• 2/18

• 3/18

• 4/18

• 6/18

Tags

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

What is 1/3 converted to a fraction with a denominator of 18?

• 6/18

• 3/18

• 4/18

• 5/18

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D

What is the result of 8/18 - 3/18 + 6/18?

• 9/18

• 12/18

• 10/18

• 11/18

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D