Mastering Percentages
Percentages are one of the most useful mathematical concepts in daily life. The word comes from the Latin per centum, meaning "by the hundred." Essentially, a percentage is just a fraction with a denominator of 100.
The Three Types of Problems
Most percentage questions fall into one of these categories:
- Find the Part: "What is 20% of 50?" (Result: 10)
- Find the Percentage: "10 is what % of 50?" (Result: 20%)
- Find the Whole: "10 is 20% of what?" (Result: 50)
Real-World Examples
Frequently Asked Questions
How do I calculate percentage change? ▼
To find the increase or decrease between two numbers,
use this formula:
((New Value - Old Value) / Old Value) × 100
If the result is positive, it's an increase. If negative,
it's a decrease.
Is percentage the same as percentile? ▼
No. A percentage is a specific value (e.g., getting 90% on a test). A percentile compares you to others (e.g., being in the 90th percentile means you scored better than 90% of test-takers).