Converting Percentages to Fractions or Decimals
We have so far converted fractions and decimals to percentages. We can also do the reverse. That is, given per cents, we can convert them to decimals or fractions. Look at the table, observe and complete it:
| Per cent | 1% | 10% | 25% | 50% | 90% | 125% | 250% |
|---|---|---|---|---|---|---|---|
| Fraction | |||||||
| Decimal | 0.10 |
Parts always add to give a whole
In the examples for coloured tiles, for the heights of children and for gases in the air, we find that when we add the Percentages we get 100.
All the parts that form the whole when added together gives the whole or 100%.
So, if we are given one part, we can always find out the other part. Suppose, 30% of a given number of students are boys.
This means that if there were 100 students, 30 out of them would be boys and the remaining would be girls.
Then girls would obviously be (100 – 30)% =
TRY THESE
Fun with Estimation
EXAMPLE5 What per cent of the adjoining figure is shaded?
SOLUTION We first find the fraction of the figure that is shaded. From this fraction, the percentage of the shaded part can be found. You will find that half of the figure is shaded. And