Adding and Subtracting Fractions with Unlike Denominators

What is the first step in adding or subtracting fractions with different denominators?

• Multiply the fractions

• Subtract the denominators

• Find the least common multiple

• Add the numerators

Tags

CCSS.7.NS.A.1C

How do you find the least common multiple of two numbers?

• Add them together

• Find the highest number that divides both

• List multiples of each and find the smallest common one

• Multiply them

To keep fractions equivalent when changing denominators, what must you do to the numerator?

• Add the original denominator

• Multiply by the same number as the denominator

• Divide by the new denominator

• Nothing

Tags

CCSS.3.NF.A.3A

CCSS.3.NF.A.3B

CCSS.4.NF.A.1

What happens to the denominators when adding fractions with a common denominator?

• They are multiplied

• They are subtracted

• They remain unchanged

• They are added together

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D

What is the least common multiple of 9 and 3?

• 9

• 27

• 3

• 18

After finding a common denominator and adjusting fractions, what is the next step?

• Multiply the fractions

• Change the denominators again

• Add or subtract the numerators

• Simplify the fractions

Tags

CCSS.7.NS.A.1C

When subtracting fractions and the numerators are subtracted, what do you do with the denominator?

• It is divided by 2

• It is also subtracted

• It remains the same

• It is multiplied by 2

Tags

CCSS.4.NF.B.3C

CCSS.4.NF.B.3D

Why is it important to simplify fractions before adding or subtracting?

• It makes the fractions larger

• It changes the value of the fractions

• It's not necessary

• It makes finding a common denominator easier

What is the least common denominator of 15 and 20?

• 30

• 40

• 5

• 60

What is the result of simplifying 55/60?

• 55/60

• 5/6

• 9/10

• 11/12