Adding and Subtracting Fractions with Unlike Denominators

When the denominators are not the same, I must find a...

• common numerator

• common denominator

• equivalent fraction

• mixed number

When adding or subtracting fractions, I NEVER add or subtract the...

• numerators

• denominators

• mixed numbers

• equivalent fractions

Once I have completed adding or subtracting fractions, I should always ____________ if possible.

• make equivalent fractions

• add again

• simplify

• multiply

Is this a correct answer?

• Yes, the student correctly added.

• No, you cannot add unlike denominators

• No, 5 + 7 is not 12

• No, 2 + 3 is not 5

What is the first step in solving this problem? 
⅘ + ½ =

• Add the top parts of the fraction

• Rewrite the fractions in the simplest form. 

• Find a common denominator. 

• Make each fraction into an improper faction. 

Aden is helping his dad paint his house. They mixed 5/9 gallons of white paint and 1/6 gallons of blue paint. How many gallons was the mixture in all?

• 6/18 gallons

• 13/18 gallons

• 4/5 gallons

• 1/6 gallons

What is the best common denominator for this problem?

• 5

• 2

• 20

• 10

Stacy used 1/4 cup of sugar and 2/3 cup of flour to bake a cupcakes. How much more flour did Stacy use than sugar?

• 11/12 cup

• 10/12 cup

• 6/12 cup

• 5/12 cup

When you add or subtract fractions with unlike denominators you..

• Find the greatest common factor to change your denominator

• Change the denominator by picking a random number then divide

• Find the least common multiple to change your denominator

• none of these are true

3/4 - 2/10

• 11/20

• 9/10

• 11/24

• 9/4