Rules for Multiplying Fractions

Which of the following statements summarizes multiplying fractions?

• Multiply the Tops and Multiply the Bottoms.

• Cross Simplify

• Find a common denominator, then multiply

• Multiply the numerators and keep the common denominator

When multiplying a fraction times a whole number, how do you convert the whole number to a fraction?  For Example:

 $\frac{3}{5}\times4$ 

• put the 4 in front of the 3/5

• put the 4 over a 1:     $\frac{4}{1}$  

• put the 4 under a 1:  $\frac{1}{4}$  

• change the 4 to a common denominator

When multiplying fractions, you must always have common denominators.

• True

• False

Which of the following is a mixed number?

• $\frac{4}{7}$

• $\frac{9}{2}$

• $5\frac{3}{4}$

• 4.85

Which of the following is a proper fraction?

• $\frac{4}{7}$

• $\frac{9}{2}$

• $5\frac{3}{4}$

• 4.85

Which of the following is an improper fraction?

• $\frac{4}{7}$

• $\frac{9}{2}$

• $5\frac{3}{4}$

• 4.85

When multiplying mixed numbers, first, you must . . . . . 

example:   $5\frac{2}{3}\times4\frac{1}{2}$  

• multiply the whole numbers times each other (5x4)

• add the whole numbers (5+4)

• Change the mixed numbers to improper fractions $\frac{17}{3}\times\frac{9}{2}$  (MAPO)

• Find common denominators

In 6th grade, when we change a mixed number to improper, Mr. Cochran and Mr. Baker call it . . . 

• ZAPPO

• Move it or lose it

• WACKO

• MAPO

Change the mixed number to improper:  $7\frac{2}{3}$  

•  $\frac{14}{3}$  
  

•  $\frac{12}{3}$  

•  $\frac{23}{3}$  

•  $\frac{42}{3}$  
  

 $\frac{2}{3}\times\frac{2}{5}=$  

•  $\frac{4}{8}$  

•  $\frac{16}{15}$  

•  $\frac{6}{10}$  

•  $\frac{4}{15}$