Adding and Subtracting Fractions

Adding/Subtracting Fractions

By Joshua Law

Multiply RIGHT fraction by LEFT Denominator, and LEFT fraction by RIGHT denominator.

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​Step 1: Common Denominator

Multiple Choice

$$\frac{3}{4}+\frac{5}{6}$$  

What would you multiply the RIGHT fraction by?

• 3

• 4

• 5

• 6

Multiple Choice

$$\frac{3}{4}+\frac{5}{6}$$  

What would you multiply the LEFT fraction by?

• 3

• 4

• 5

• 6

Multiple Choice

$$\frac{3}{4}+\frac{5}{6}$$  

Which choice shows the correct multiplication?

• $$\frac{18}{24}+\frac{20}{24}$$  

• $$\frac{18}{4}+\frac{20}{6}$$  

• $$\frac{18}{10}+\frac{20}{10}$$  

• $$\frac{3}{24}+\frac{5}{24}$$  

Multiple Choice

$$\frac{1}{2}-\frac{3}{5}$$  

Which choice shows the problem re-written with correct common denominators?

• $$\frac{5}{7}-\frac{6}{7}$$  

• $$\frac{5}{2}-\frac{6}{5}$$  

• $$\frac{5}{10}-\frac{6}{10}$$  

• $$\frac{1}{10}-\frac{3}{10}$$  

Multiple Choice

$$\frac{3}{8}-\frac{1}{3}$$  

Which choice shows the problem re-written with correct common denominators?

• $$\frac{9}{11}-\frac{8}{11}$$  

• $$\frac{3}{24}-\frac{1}{24}$$  

• $$\frac{9}{8}-\frac{8}{3}$$  

• $$\frac{9}{24}-\frac{8}{24}$$  

Fill in the Blanks

Rewrite the problem with common denominators:

$\frac{1}{2}+\frac{2}{3}$  

Type fractions using " / ". Example: $-\frac{1}{6}+\frac{7}{6}$  is -1/6+7/6

NO SPACES

Add/Subtract JUST the numerators and keep the denominator.

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​Step 2: Add/Subtract Numerators​

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Multiple Choice

Which choice shows the correct addition/subtraction step?

$$\frac{18}{24}+\frac{20}{24}$$  

• $$\frac{38}{24}$$  

• $$\frac{38}{48}$$  

• $$\frac{2}{24}$$  

• $$-\frac{2}{24}$$  

Multiple Choice

Which choice shows the correct addition/subtraction step?

$$\frac{5}{10}-\frac{6}{10}$$  

• $$\frac{1}{10}$$  

• $$-\frac{1}{10}$$  

• $$\frac{11}{20}$$  

• $$-\frac{11}{10}$$  

Fill in the Blanks

Add/Subtract the Fractions below

$\frac{9}{24}-\frac{8}{24}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Fill in the Blanks

Add/Subtract the Fractions below

$\frac{3}{6}+\frac{4}{6}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

If the numerator and denominator are divisible by the same number, divide each by that number.​

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​Step 3: Reduce, if possible​

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Multiple Choice

Which number below evenly divides both the numerator and denominator?

$$\frac{38}{24}$$  

• 8

• 6

• 2

• 3

Multiple Choice

$$\frac{38}{24}$$  

Which choice shows the fraction reduced properly?

• $$\frac{14}{12}$$  

• $$\frac{19}{12}$$  

• $$\frac{16}{8}$$  

• $$\frac{19}{6}$$  

Fill in the Blanks

Reduce the fraction below

$\frac{15}{12}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Fill in the Blanks

Reduce the fraction below

$\frac{8}{16}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Fill in the Blanks

Reduce the fraction below

$\frac{49}{42}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Let's see the whole process

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Time to show off your fraction skills!

Multiple Choice

$$-\frac{5}{3}+\frac{3}{4}$$  

• $$\frac{35}{12}$$  

• $$-\frac{15}{12}$$  

• $$-\frac{11}{12}$$  

• $$-\frac{8}{7}$$  

Multiple Choice

$$\frac{7}{6}-\frac{5}{3}$$  

• $$-\frac{3}{6}$$  

• $$-\frac{51}{18}$$  

• $$-\frac{9}{18}$$  

• $$-\frac{1}{2}$$  

Fill in the Blanks

$\frac{11}{6}+\frac{5}{6}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Fill in the Blanks

$\frac{2}{3}+\frac{3}{7}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES

Fill in the Blanks

$-\frac{4}{5}-\frac{4}{9}$  

Type fractions using " / ". Example: $-\frac{1}{6}$  is -1/6

NO SPACES