Common Denominators for Adding and Subtracting Fractions

Find equivalent fractions with common denominators for the problem shown above.

• 4/15 and 2/15

• 24/30 and 20/30

• 12/15 and 2/15

• 12/15 and 10/15

Solve.

• 1 1/12

• 7/12

• 3/4

• 1 1/2

Solve.

• 5/8

• 23/40

• 21/40

• 1/2

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

Adding & Subtracting Fractions with

UNLIKE Denominators

• I'm ready to try

• Let's do this!

• I'm not sure about these.

Solve and simplify to lowest terms

• A

• B

• C

• D

In the case that the given fractions are dissimilar, how shall we make them similar being the only way to proceed to addition or subtraction of fractions?

• Add the denominators together. Whatever is the sum, that will be the denominator for both fractions.

• Just choose either of the denominator from both fractions that you wanted as new denominator before you proceed to adding and subtracting the numerators.

• Simply find LCD and use such LCD as the new denominator for both fractions. Then find equivalent fractions for each given.

• All of the above.

Add and simplify if needed. 3/4 + 1/8 =

• 7/8

• 4/8

• 7/32

• 4/32

What is the least common denominator of 1/2 and 3/7?

• 2

• 14

• 7

• 28

• 1 4/15

• 2 5/15

• 1 5/15

• 2 4/15