To find the percentage of a number, the most common formula used is:
Percentage=(PartWhole)×100\text{Percentage}=\left(\frac{\text{Part}}{\text{Whole}}\right)\times 100Percentage=(WholePart)×100
This means you divide the part by the whole and then multiply the result by 100 to get the percentage. For example, if you want to find what percentage 10 is of 40, you calculate:
1040×100=25%\frac{10}{40}\times 100=25%4010×100=25%
Alternatively, to find a certain percentage of a number (for example, 20% of 1200), you multiply the number by the percentage (expressed as a decimal):
Percentage of a number=Percent×Number=Percent100×Number\text{Percentage of a number}=\text{Percent}\times \text{Number}=\frac{\text{Percent}}{100}\times \text{Number}Percentage of a number=Percent×Number=100Percent×Number
Example:
20% of 1200=20100×1200=24020%\text{ of }1200=\frac{20}{100}\times 1200=24020% of 1200=10020×1200=240
In summary:
- To find what percentage one number is of another, divide and multiply by 100.
- To find a percentage of a number, convert the percentage to a decimal and multiply.
These are the fundamental ways to calculate percentages.
