Understanding Sine Fractions and Least Common Denominator

The video tutorial explains how to add fractions with different denominators by finding the least common denominator (LCD). It demonstrates two methods: identifying the LCD by inspection and using prime factorization. Two examples are provided to illustrate the process, showing how to rewrite fractions with a common denominator and combine them. The tutorial emphasizes the importance of understanding prime factorization to determine the LCD when it is not immediately obvious.

What is the first step when adding fractions with different denominators?

• Multiply the numerators

• Add the numerators

• Subtract the denominators

• Find a common denominator

What is the least common denominator (LCD) of 8 and 12?

• 16

• 28

• 20

• 24

How can you determine the LCD using prime factorization?

• By adding the numerators

• By ensuring the prime factors in the denominators are the same

• By multiplying the denominators

• By subtracting the denominators

Tags

CCSS.7.NS.A.1C

What is the sum of -9/24 and -10/24?

• -19/24

• -1/24

• 19/24

• 1/24

What is the least common denominator of 20 and 8?

• 60

• 50

• 40

• 30

Tags

CCSS.3.NF.A.1

CCSS.3.NF.A.2B

In the second example, what factor is missing in the denominator of the first fraction?

• 2

• 3

• 7

• 5

Tags

CCSS.7.NS.A.1C

What is the sum of -6/40 and 5/40?

• -1/40

• 1/40

• -11/40

• 11/40

Why is prime factorization helpful in finding the LCD?

• It subtracts the numerators

• It adds the denominators

• It ensures the denominators have the same prime factors

• It simplifies the numerators

What is the prime factorization of 20?

• 2 x 3 x 5

• 2 x 2 x 5

• 2 x 2 x 3

• 3 x 3 x 5

What is the prime factorization of 8?

• 2 x 2 x 2

• 2 x 2 x 3

• 2 x 3 x 3

• 3 x 3 x 3