Review: Adding Fractions

​Adding Fractions with Unlike Denominators

Uncommon Denominator

A fraction that has the bottom number that is not the same. Or when two fractions have different denominators.

How can we find a common denominator?

​The denominator need to be the same for both fractions

We need to multiply both denominator and numerator by the same number.

​Equivalent Fractions

Common Denominator

​x

​x

2

2

6

4

​x

​x

5

5

15

10

Multiple Choice

What is an equivalent fraction to $$\frac{1}{2}$$ ?

• $$\frac{2}{3}$$

• $$\frac{4}{6}$$

• $$\frac{5}{10}$$

• $$\frac{3}{8}$$

Multiple Choice

What is an equivalent fraction to $$\frac{2}{3}$$ ?

• $$\frac{3}{6}$$

• $$\frac{6}{9}$$

• $$\frac{8}{15}$$

• $$\frac{4}{9}$$

Multiple Choice

What is an equivalent fraction to $$\frac{3}{4}$$ ?

• $$\frac{6}{12}$$

• $$\frac{12}{20}$$

• $$\frac{6}{8}$$

• $$\frac{9}{15}$$

Multiple Choice

What is an equivalent fraction to $$\frac{2}{5}$$ ?

• $$\frac{10}{25}$$

• $$\frac{12}{20}$$

• $$\frac{6}{10}$$ 12

• $$\frac{10}{30}$$

Common Denominator:

Both numerator and denominator need to be the same in order for us to add them.

Problem #1

​1

5

​2

4

+

=

Fill in the Blank

What is my common denominator between 5 and 4?

Problem #1

​1

5

​2

4

+

=

20

20

Problem #1

​1

5

​2

4

+

=

20

20

​x5

​4x

Multiple Choice

What I do to the numerator I also.....

• need to do to the terminator

• need to add

• need to do to the denominator

Problem #1

​1

5

​2

4

+

=

20

20

​x5

​4x

​4x

​x5

4

10

Multiple Choice

$$\frac{1}{5}$$ + $$\frac{2}{4}$$ =

• $$\frac{14}{20}$$

• $$\frac{3}{20}$$

• $$\frac{10}{4}$$

• $$\frac{3}{9}$$

Problem #2

​2

5

​1

10

+

=

50

Problem #2

​2

5

​1

10

+

50

=

50

50

​10x

​x5

Multiple Choice

$$\frac{2}{5}$$ is equivalent to $$\frac{ }{50}$$ ?

• $$\frac{3}{50}$$

• $$\frac{15}{50}$$

• $$\frac{20}{50}$$

Problem #2

​2

5

​1

10

+

50

=

50

50

​10x

​x5

20

​10x

Multiple Choice

$$\frac{1}{10}$$ is equivalent to $$\frac{ }{50}$$ ?

• $$\frac{3}{50}$$

• $$\frac{5}{50}$$

• $$\frac{10}{50}$$

Problem #

​1

5

​2

4

+

=

20

20

​x5

​4x

​4x

​x5

4

10

Problem #2

​2

5

​1

10

+

50

=

50

50

​10x

​x5

20

​10x

​x5

5

Problem #2

​2

5

​1

10

+

=

50

Poll

$$\frac{2}{5}$$ + $$\frac{1}{10}$$ =

• $$\frac{3}{50}$$

• $$\frac{5}{20}$$

• $$\frac{7}{11}$$

• $$\frac{25}{50}$$

Let's Practice adding fractions with unlike denominators

Multiple Choice

$$\frac{5}{6}$$ + $$\frac{5}{11}$$ =

• $$\frac{85}{66}$$

• $$\frac{66}{55}$$

• $$\frac{11}{66}$$

• $$\frac{10}{17}$$

Multiple Choice

$$\frac{2}{5}$$ + $$\frac{1}{8}$$ =

• $$\frac{3}{40}$$

• $$\frac{21}{40}$$

• $$\frac{6}{16}$$