Add and Subtract Fractions with Unlike Denominators

8/9 - 1/3 = 

• 7/6

• 5/9

• 2/3

• 8/27

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What number could be a common denominator for these two fractions?
2/3   and   3/4

• 3

• 4

• 7

• 12

What is the sum?

• 1

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Find the difference.

Tags

CCSS.7.NS.A.1C

What is the sum of these fractions?

• 4/5

• 3/20

• 17/20

• 4/20

Tags

CCSS.7.NS.A.1C

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

What is the sum?

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

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

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

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