Converting Percentages to Decimals

To convert a percentage to a decimal, divide by 100.

Note that, to divide by 100, you need to move the decimal point two places to the left.

Example 10.2.1:

Change these to decimals.

(i) 35%
(ii) 70%
(iii) 20¾ %
(iv) 9.8%

Solution

(i) 35%     =  \( \frac{35}{100} \\ = \scriptsize 0.35\)

(ii) 70% = \( \frac{70}{100} \\ = \frac{7}{10} \\ = \scriptsize 0.7 \)

(iii) 20¾ %  

= \( \frac{\large\frac{83}{4}}{100} \\ = \frac{83 \: \times \: 1}{4 \: \times \: 100} = \frac{83}{400} \\ = \scriptsize 0.2075\)

(iv) 9.8%  = \( \frac{9.8}{100} \\ = \scriptsize 0.98 \)