Add and Subtract Fractions with Unlike Denominators

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

Tags

CCSS.7.NS.A.1C

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

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

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

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Carefully following a recipe, Ben used exactly 5/8 of a cup of oil and 3/4 of a cup of water. How many cups of liquid did Ben use in all?

• 1/8

• 2/3

• 1 1/2

• 1 3/8

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the sum of these fractions?

• 4/5

• 3/20

• 17/20

• 4/20

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the sum of these fractions in lowest terms?

• 4/5

• 3/20

• 17/20

• 4/20

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Marty made two types of cookies.  He used 2/3 cup of sugar for one recipe and 1/4 cup  of sugar for the other.  How much sugar did he use in all? 

• 5/12

• 3/7

• 11/12

• 1/3

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the sum?

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Find the difference.

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

8/9 - 1/3 = 

• 7/6

• 5/9

• 2/3

• 8/27

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2