Adding and Subtracting 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

3/4 - 2/10

• 11/20

• 9/10

• 11/24

• 9/4

4/5 + 3/8 (be sure to simplify)

• 32/40

• 1 7/40

• 2 5/7

• 1 1/2

5/10 + 8/5

• 5/9

• 1/10

• 2 1/10

• 2 2/10

Solve and simplify if needed:

1/3 - 1/5 =

Mathematical Equivalence

OFF

What is the sum of these fractions in lowest terms?

• 4/5

• 3/20

• 17/20

• 4/20

3/5 - 5/10

• 1/10

• 8/5

• 1/5

• 8/0

Pick the steps that are true

• find the common denominators, add or subtract, change the numerators

• multiply the denominators, add or subtract the numerators, simplify, divide the fraction

• Find the least common denominators, what you do to the top do to the bottom, add or subtract, simplify

• add or subtract, simplify, multiply denominators

How do you find the common denominator when adding fractions with unlike denominators?

• By multiplying the denominators together

• By finding the greatest common factor

• By finding the least common multiple

• By adding the denominators together

The bottom number of a fraction is called the ______________