Add and Subtract Fractions with Unlike Denominators Word Problems

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

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

Simon has 1/5 of a gallon of cranberry juice, 1/3 of a gallon of apple juice, and 7/10 of a gallon of grape juice. How much juice does Simon have?

• 9/30

• 1/2

• 1  7/30

• 1  13/30

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. 

What does Ms. Parten say you should think of when you see unlike denominators?

• green flag

• white flag

• pizza

• red flag

What is the sum?

• 1

What is the sum?

(Choose one that is true) 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

What is the the next step to finding this answer?

• Add the numerators (1+1=2)

• Multiply 12 X 1 for both fractions to find a new numerator
  

• Multiply to find each new numerator by the multiple used to get 12. (3 X1) (4 X 1)

• This is a mistake, you don't need to convert to twelfths