Dividing Fractions

Concept sheet | Mathematics

Dividing Fractions

When dividing two fractions, remember that dividing is the same as multiplying one fraction by the reciprocal of the other. 

Rule

For example, to divide the fractions |\dfrac{1}{2}\div\dfrac{1}{3},| we follow these steps:

  1. We invert the numerator and denominator of the fraction on the right. 

    ||\frac{1}{2}\div\frac{3}{1}||
     
  2. We change the division sign to a multiplication sign.

    ||\frac{1}{2}{\color{red}\times} \frac{3}{1}||
     
  3. We multiply the fractions.

    ||\frac{1}{2}\times \frac{3}{1} =\frac{3}{2}||
Example

||\frac{2}{3}\div\frac{1}{9}=\frac{2}{3}\times\frac{9}{1}=\frac{2\times9}{3\times1}=\frac{18}{3}=6||


||\frac{4}{5}\div\frac{2}{3}=\frac{4}{5}\times\frac{3}{2}=\frac{4\times3}{5\times2}=\frac{12}{10}=\frac{6}{5}||

Important!
  • When dividing 2 numbers with the same sign, the quotient will be positive.
     
  • When dividing 2 numbers with opposite signs, the quotient will be negative.

Dividing Mixed Numbers

When dividing mixed numbers, first convert the mixed numbers into fractions, and then perform the operation as explained above.

Example

||4\frac{1}{3}\div\frac{2}{5}=\frac{13}{3}\div\frac{2}{5}=\frac{13}{3}\times\frac{5}{2}=\frac{65}{6}=10\frac{5}{6}||


||8\frac{1}{2}\div4\frac{1}{3} =\frac{17}{2}\div\frac{13}{3}=\frac{17}{2}\times\frac{3}{13} =\frac{51}{26}||