Adding and subtracting 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

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

1/2 + 1/3 =

• 1/6

• 3/6

• 5/6

• 6/6

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

7/10 + 2/4

• 12/10

• 8/12

• 6/5

• 1 and 1/5

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

6/10 + 2/3

• 19/15

• 1 and 4/15

• 8/13

• 12/30

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

8/9 - 5/6 = 

• 4/18
• 1/18
• 3/18

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

• 1/12
• 1
• 2/35
• 23/25

Tags

CCSS.7.NS.A.1C

What is 9/10 - 3/4?

• 5/7
• 3/20
• 3/8 
• 9/10

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

Answer explanation

Don't forget to regroup from the whole number 7. When I borrow 1 whole from the 7 it turns into 6. The pieces I borrowed from my whole I can add to my numerator to help me subtract.  

Tags

CCSS.7.NS.A.1C

Answer explanation

Don't forget to regroup from the whole number 9. When I borrow 1 whole from the 9 it turns into 8. The pieces I borrowed from my whole I can add to my numerator to help me subtract.  

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2