Percentages are a way to express a number as a fraction of 100.
Common Applications:
- Basic Percentage: Find X% of a number
- Percentage Change: Increase or decrease by X%
- Discounts: Calculate sale prices and savings
- Tips: Calculate restaurant tips and service charges
Quick Tips:
- 10%: Move decimal one place left
- 20%: Double 10% value
- 25%: Divide by 4
- 50%: Divide by 2
- 100%: The entire amount
Common Tip Rates:
- 15%: Standard service
- 18%: Good service
- 20%: Excellent service
- 25%+: Outstanding service
Remember that percentages are always calculated relative to the original amount unless specified otherwise.