Finding Percentages Quickly
- Trick / Shortcut
- Finding Percentages Quickly
- Topic
- Percentages
- How It Works
Break down complex percentages into simpler, easier-to-calculate components:
- $10%$: Move the decimal point one place to the left.
- $5%$: Half of $10%$.
- $1%$: Move the decimal point two places to the left.
- $25%$: Divide by 4.
- $33.33%$ (or $33 \frac{1}{3}%$): Divide by 3 (approximate).
- $50%$: Divide by 2.
- $75%$: Three-quarters of the number (e.g., $50% + 25%$).
Use these building blocks to compute any percentage.
- Example
$35%$ of 240:
- $10%$ of $240 = 24$
- $30%$ of $240 = 3 \times (10%) = 3 \times 24 = 72$
- $5%$ of $240 = \frac{1}{2} \times (10%) = \frac{1}{2} \times 24 = 12$
- $35%$ of $240 = 30% + 5% = 72 + 12 = \textbf{84}$
$15%$ of 360:
- $10%$ of $360 = 36$
- $5%$ of $360 = \frac{1}{2} \times (10%) = \frac{1}{2} \times 36 = 18$
- $15%$ of $360 = 10% + 5% = 36 + 18 = \textbf{54}$