SF-7S Semester Math Review: x and ÷ Fractions

SF-7S Semester Math Review: x and ÷ Fractions

Important Tips for Multiplying and Dividing Fractions and Mixed Numbers!

When multiplying fractions, you DO NOT need common denominators (yay!).

Just multiply across.

Cross reduce if you are able to avoid multiplying large numbers.

To cross reduce, divide the numerator of one fraction and the denominator of the other by a common factor.

When multiplying mixed numbers, change the mixed number to an improper fraction (washing machine) and then multiply as you normally would.

If you are multiplying a fraction or mixed number by a whole number, make the whole number a fraction.

Multiple Choice

Try this one:

 $\frac{2}{15}\times\frac{3}{16}=$  

•  $\frac{1}{40}$  

•  $\frac{6}{240}$  

•  $\frac{5}{31}$  

Multiple Choice

Try one more:

 $2\times2\ \frac{3}{4}=$  

•  $\frac{11}{2}$  

•  $5\ \frac{1}{2}$  

•  $1\ \frac{2}{5}$  

When dividing fractions or mixed numbers, Remember to ALWAYS Keep, Change, Flip!

When dividing mixed numbers, first "washing machine" the mixed number/s. Then, Keep, Change, Flip!

Multiple Choice

Try this one:

 $\frac{1}{4}\div\frac{1}{2}=$  

•  $\frac{1}{8}$  

•  $\frac{1}{2}$  

•  $\frac{2}{4}$  

Multiple Choice

Try one more:

 $8\ \frac{1}{2}\div5$  

•  $1\ \frac{7}{10}$  

•  $\frac{17}{10}$  

•  $42\ \frac{1}{2}$  

If you are feeling comfortable, you may begin solving Midterm Review Packet problems 49-55. You will input your answers on the following slides.

Fill in the Blank

Midterm Review Packet question 49:

 $\frac{3}{14}\times\frac{7}{15}=$  

Fill in the Blank

Midterm Review Packet question 50:

 $3\ \frac{3}{4}\times2\ \frac{4}{5}=$  

Fill in the Blank

Midterm Review Packet question 51:

 $6\ \frac{1}{2}\times2=$  

Fill in the Blank

Midterm Review Packet question 52:

 $8\times2\ \frac{3}{4}=$  

Fill in the Blank

Midterm Review Packet question 53:

 $1\ \frac{2}{3}\div2\ \frac{4}{9}=$  

Fill in the Blank

Midterm Review Packet question 54:

 $15\div4\ \frac{1}{5}=$  

Fill in the Blank

Midterm Review Packet question 55:

 $8\ \frac{1}{2}\div5=$  

Corrections:

If you answered any of the questions incorrectly, go back and make corrections.