Converting Percentages to Decimals

Converting Percentages to Decimals

We have seen conversion of decimals to percentage. We can also do the reverse process, that is when the percentage is given we can convert them to decimals.

Example 2.11

Convert the given percentage to decimals.

 (i) 58%  (ii) 8%  (iii) 30%  (iv) 120%    (v) 1.25%

Solution:

(i) 58% =58/100 = 0.58

(ii) 8% = 8/100 = 0.08

(iii) 30% = 30/100 = 0.3

(iv) 120% = 120/100 = 1.2

(v) 1.25% = 1.25/100 = 0.0125

From the above examples we see that to convert percentage to decimals we first convert it into fraction and get the solution.

Try these

Write these percentage as decimals.

(i) 3% ( ii) 25% (iii) 80% ( iv) 67% (v ) 17.5% ( vi ) 135% (vii) 0.5%

Solution:

(i) 3% = 3/100 = 0.03

(ii) 25% = 25/100 = 0.25

(iii) 80% = 80/100 = 0.8

(iv) 67% = 67/100 = 0.67

(v) 17.5% = 17.5 / 100 = 0.175

 (vi) 135% = 135/100 = 1.35

(vii) 0.5% =  0.5/100 = 0.005

Example 2.12

Malar bought 1.75 m of fabric from a roll of 25 m. Express the fabric bought in terms of percentage?

Solution:

Total length of the fabric = 25 m

Length of the fabric bought = 1.75 m

Percentage of the fabric bought = (1.75/25) × (100/100) = 175/ (25/100) = 7/100 = 7%

Area as Percentage

Percentages also help us to estimate the area.

Example 2.13

How many per cent in the Fig. 2.3 is shaded as blue?

Solution:

The fraction in the Fig. 2.3, that is shaded = 2/4 = 1/2 .

That is half of the Fig. 2.3 is shaded blue.

So, the percentage of shaded portion = (1/2) × 100% = 50%

Thus, 50% of the Fig. 2.3 is shaded.