5.3H Adding & Subtracting Fractions unlike denominators

5.3H Adding & Subtracting Fractions unlike denominators

By the end of this lesson you will be able to...

• Identify the numerator and the denominator in a fraction

• Add fractions with both like and unlike fractions

• Subtract fractions with both like and unlike fractions

Vocabulary

• Numerator

• Denominator

• Improper Fraction

• Mixed Number

• Symplify

Like Fractions

When fractions have the same denominator they are like fractions.

You can add or subtract fractions when you have like fractions.

 $\frac{4}{5},\ \frac{7}{5},\ \frac{6}{5},\ \frac{3}{5},\ \frac{2}{5},\ \frac{5}{5}$  

These are like fractions 

Unlike Fractions

Unlike fractions have different denominators.

Adding or subtracting unlike fractions isn't that different from adding or subtracting like fractions. You just have to find what their denominator have in common.

 $\frac{2}{3},\ \frac{3}{4},\frac{5}{6},\ \frac{5}{8}$  

Changing Unlike to Like denominator

• Find a common multiple that will go into both denominators.

We DO

Changing Unlike to Like Denominators

 $\frac{2}{5}+\frac{5}{7}=$  

Find a common denominator 
 $\frac{2}{5}$  =                                                                      

 $\frac{5}{7}$ =                                                                      

Multiple Choice

What is the least common denominator of 

 $\frac{1}{4}$  and  $\frac{2}{5}$  

• 5

• 25

• 10

• 20

Multiple Choice

What is the least common denominator of 

 $\frac{6}{8}$  and  $\frac{4}{12}$   

• 12

• 24

• 8

• 16

WeDo....

Once you find the common denominator add the fractions together

 $\frac{2}{5}+\frac{5}{7}=$  

Common Denominator is __________
Rewrite the fraction (WHATEVER YOU DO TO THE TOP YOU MUST DO TO THE BOTTOM) 

Multiple Choice

 $\frac{2}{6}+\frac{1}{2}$  

• 5/6

• 3/6

• 4/6

• 3/8

Multiple Choice

 $\frac{9}{10}-\frac{3}{4}$  

• 5/7

• 3/20

• 3/8 

• 9/10

DOL

NEXT.........

Multiple Choice

Jessica rode her bike  $8\ \frac{5}{9}$   miles last week and  $5\ \frac{1}{3}$  miles this week. How many miles did Jessica ride last week and this week combined?

•  $13\ \frac{1}{2}$  

•  $13\ \frac{8}{9}$  

•  $3\ \frac{2}{9}$  

•  $12\ \frac{5}{9}$  

Multiple Choice

Blake had 2/3 of a cake left after his birthday party. His sister, Bethany, ate 1/6 of the leftover cake. How much cake is left?

• 1/6

• 1/9

• 3/5

• 1/2

Breakout Rooms

We're going to split into groups and continue to practice our skills.