Percentage - Finding Percentage of a Number

The word percentage comes from the Latin 'per centum', meaning 'per hundred'. You can visualize this as a 10 by 10 grid containing 100 small squares; if you color 15 squares, you have shaded $15\%$ of the grid.

The symbol for percentage is $\%$. When we see $20\%$, it represents the fraction $\frac{20}{100}$ or the decimal $0.20$.

To find the percentage of a specific number, we treat the word 'of' as a mathematical instruction to multiply. For example, '$5\%$ of $60$' translates to $\frac{5}{100} \times 60$.

A percentage can be visualized using a bar model. If a full bar represents $100\%$ (the whole number), then $50\%$ would be exactly half of the bar, and $25\%$ would be one-quarter of that bar.

When calculating the percentage of a number, the resulting value will carry the same units as the original number. For instance, $10\%$ of $500$ grams is $50$ grams, not just $50$.

Simplifying the calculation often involves 'canceling zeros'. If you are calculating $\frac{10}{100} \times 200$, you can remove two zeros from both the denominator $100$ and the number $200$ to make the math easier: $10 \times 2 = 20$.

Understanding benchmarks helps in estimation. $100\%$ of a number is the number itself, $50\%$ is half of the number, and $10\%$ is the number divided by $10$.