Subtracting Mixed Numbers with Unlike Denominators

Subtracting Mixed Numbers with Unlike Denominators

Review and Practice!

Steps to solving a subtraction of mixed numbers with unlike denominators

• Check the denominators

• Find the LCM if different, and make equivalent fractions

• Check the numerators

• If you can subtract, yay! If you can't, borrow from the whole or change BOTH to improper fractions

• Subtract fractions

• Subtract whole numbers

• Simplify (little divide)

Multiple Select

How do you find common denominators?

• Find the GCF

• Find the LCM

• Make up a number

• Choose a number divisible by 100

Poll

What is the difference of 2/3 and 1/4?

• 5/12

• 2/12

• 3/4

• 2/7

Multiple Choice

What is 6  $\frac{2}{3}$  -  4  $\frac{1}{4}$  

• 2 $\frac{1}{2}$  

• 2  $\frac{2}{3}$  

• 2 $\frac{3}{8}$  

• 2  $\frac{5}{12}$  

Poll

What is 3-6?

• 3

• 0

• 9

• Can't do it

Poll

Can we subtract these mixed numbers properly?
5 $\frac{7}{8}$  - 1  $\frac{3}{8}$  

• Yes

• No

Multiple Select

What are the 2 strategies we have when the numerator from the top fraction is smaller than the bottom numerator? Choose all that apply.

• Change JUST the top to an improper fraction

• Change BOTH to an improper fraction

• Regroup from the whole number and add a whole to the original fraction in fraction form.

• Change from a mixed number to a simplified fraction

• Make an equivalent fraction for the bottom fraction only.

Multiple Choice

How do we change mixed numbers to improper fractions?

• Add the denominator and numerator, then multiply the whole number

• Add the whole number and numerator, then multiply the denominator

• Multiply the denominator and numerator, then add the whole number

• Multiply the denominator and whole number, then add the numerator.

Poll

Turn this mixed number into an improper fraction.

 $4\ \frac{2}{7}$  

•  $\frac{24}{8}$  

•  $\frac{28}{7}$  

•  $\frac{30}{7}$  

Multiple Choice

Subtract and find the answer in simplest form.

 $5\frac{2}{9}$  - 2 $\frac{2}{3}$  

• 2 $\frac{5}{9}$  

• 3 $\frac{0}{6}$  

• 3 $\frac{4}{9}$  

Multiple Choice

 $4\ \frac{1}{8}-1\ \frac{5}{8}$  
Find the difference in simplest form

• 2  $\frac{3}{8}$  

• 3

• 3  $\frac{1}{2}$  

• 2  $\frac{1}{2}$  

Multiple Choice

 $3-2\frac{1}{7}$  

• 6/7

• 1  $\frac{6}{7}$  

• 5/7

• 5  $\frac{6}{7}$  

Multiple Choice

 $6\ \frac{1}{4\ }-2\ \frac{6}{8}$  

 

• 3 $\frac{1}{2}$  

• 3  $\frac{3}{4}$  

• 4  $\frac{1}{2}$  

• 4  $\frac{1}{4}$  

Multiple Choice

Solve this equation:

 $4\ \frac{5}{6\ }-2\ \frac{1}{3}$  

• 2  $\frac{1}{2}$  

• 2  $\frac{1}{3}$  

• 1  $\frac{5}{6}$  

Multiple Choice

Solve. Find the difference in simplest form.
 $6\ \frac{2}{4}-\ 2\ \frac{2}{5}$  

• 5  $\frac{2}{7}$  

• 4  $\frac{2}{20}$  

• 6  $\frac{1}{2}$  

• 4  $\frac{1}{10}$  

Multiple Choice

Find the difference in simplest form.
 $8\ \frac{5}{7}-\ 7\ \frac{2}{3}$  

 

• 1  $\frac{3}{4}$  

• 1  $\frac{1}{21}$  

• 1   $\frac{1}{24}$  

• 1   $\frac{3}{24}$