Meaning of Percentage
Per cent is derived from Latin word ‘per centum’ meaning ‘per hundred’
| 1 | = | 0.01 |
| 100 |
| Part | = | % |
| Whole | 100 |
To understand this, let us consider the following example.
Play around with the values and see how the fractions are getting affected.
Count of yellow tiles
Count of green tiles
Count of red tiles
Rina made a table top of 100 different coloured tiles. She counted yellow, green, red and blue tiles separately and filled the table below. Can you help her complete the table?
| Colour | Number of Tiles | Rate per Hundred | Fraction | Written as | Read as |
|---|---|---|---|---|---|
| Yellow | ${yellowCnt} | ${yellowCnt} | ${yellowCnt}% | ${yellowCnt} per cent | |
| Green | ${greenCnt} | ${greenCnt} | ${greenCnt}% | ${greenCnt} per cent | |
| Red | ${redCnt} | ${redCnt} | ${redCnt}% | ${redCnt} per cent | |
| Blue | ${blueCnt} | ${blueCnt} | ${blueCnt}% | ${blueCnt} per cent | |
| Total | 100 |
Percentages when total is not hundred
In all these examples, the total number of items add up to 100. For example, Rina had 100 tiles in all, there were 100 children and 100 shoe pairs. How do we calculate Percentage of an item if the total number of items do not add up to 100? In such cases, we need to convert the fraction to an equivalent fraction with denominator 100.
Consider the following example. You have a necklace with twenty beads in two colours.
| Colour | Number | Fraction | Denominator Hundred | In Percentage |
|---|---|---|---|---|
| Red | 8 | |||
| Blue | 12 | |||
| Total | 20 |
THINK, DISCUSS AND WRITE
Look at the examples below and in each of them, discuss which is better for comparison.
In the atmosphere, 1 g of air contains:
A shirt has