Adding and Subtracting Fractions

Adding and Subtracting Fractions

EASIEST thing to do is turn mixed numbers into improper fractions first
(makes borrowing and negatives easier)

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​Mixed numbers

Multiple Choice

Turn into improper fraction

• 37/2
• 52/7
• 7/37
• 37/7

Multiple Choice

Turn into improper fraction

• 24/4
• 35/4
• 11/3
• 28/3

​Just add or subtract the numerator

KEEP the denominator

With a common denominator

Multiple Choice

$$\frac{7}{9}+\frac{5}{9}$$  

Try this!

• 4/3
• 12/9
• 2/9

• 12/18

Multiple Choice

$$\frac{11}{14}-\frac{4}{14}$$  

• 1/2
• 7/0

• 15/14

• 7/14

Fill in the Blanks

$Of\ the\ animals\ at\ the\ shelter,\ \frac{5}{8}\ are\ cats\ and\ \frac{2}{8}are\ dogs.\ \$  

What fraction of the animals in the shelter are either cats or dogs?

Multiple Choice

Solve the problem

• $$\frac{7}{10}$$  

• $$\frac{4}{5}$$  

• $$\frac{3}{10}$$  

• $$\frac{1}{5}$$  

Multiple Choice

Gideon ran  $$2\frac{4}{5}$$  miles last weekend.  This weekend he ran  $$3\frac{1}{5}$$  miles.  How many miles did he run in all?

• $$\frac{8}{5}$$  miles

• $$\frac{55}{10}$$  miles

• $$\frac{28}{5}$$  miles

• 6 miles

• $$\frac{30}{5}$$ miles

Fill in the Blanks

Jason has $\frac{2}{5}$ gallons of water. Gordon has $\frac{4}{5}$ gallons of water. Brett has $2\frac{3}{5}$ gallons of water. How much more water does Brett have than the other two students?

gallons

Adding fractions with different denominators

• Multiply the denominators (to get a common denominator - QCD)

• Multiply the numerator of the first fraction by the opposite denominator

• Multiply the numerator of the second fraction by the opposite denominator

• Add or subtract the new "numerators"

Multiple Choice

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

Multiple Choice

Subtract and simplify if you can.
2/4 - 3/8

• 1/8
• 1/4

• 4/32

• 28/32

Fill in the Blanks

7/10 - 1/2 =

in simplest form

Fill in the Blanks

Reduce if needed.

Multiple Choice

Solve the problem

• 6

• 61/12

• 59/12

• 71/12

Multiple Choice

Malique bakes 4 whole pies for Thanksgiving. After dessert is finished, she has  $$2\ \frac{1}{4}$$   pie left. How much pie did her family eat?

• $$\frac{9}{4}$$  

• $$\frac{7}{4}$$  

• $$\frac{11}{4}$$  

• $$\frac{8}{4}$$  

Multiple Choice

Monique wants to bake a cake. She needs $$2\frac{1}{8}$$ cups of sugar, and $$1\frac{5}{24}$$ cups of flour. How many cups of ingredients will she use in all?

• $$\frac{10}{3}$$ cups

• $$\frac{99}{32}$$ cups

• $$\frac{13}{4}$$ cups

• $$\frac{25}{8}$$ cups