Add Subtract Fractions Different Denominators

What is the least common denominator you could use to subtract 1/6 and 1/4?

• 24

• 16

• 20

• 12

I should use LCM (least common multiple) when trying to find a common denominator.

• true

• false

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 least common denominator for 7 and 2?

• 12

• 14

• 7

• 6

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

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

• Add both the numerators and denominators

• Change the denominator by picking a random number then divide

• Find the least common multiple of both denominators

• none of these are true

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 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. 

Tags

CCSS.5.NF.A.1

CCSS.5.NF.A.2

What is the best Common Denominator for the Given Problem?

• 48

• 24

Following the integer rules, would you add or subtract the fractions?

• add, the answer would be positive

• add, the answer would be negative

• subtract, the answer will be positive

• subtract the answer will be negative

Tags

CCSS.7.NS.A.1C