Understanding Percentages

Percentages are a fundamental concept in mathematics and are used extensively in everyday life, from calculating discounts while shopping to understanding financial growth. A percentage is a way of expressing a number as a fraction of 100. The term "percent" means "per hundred."

Common Percentage Calculations:

• Finding X% of Y: To find what X percent of Y is, you can use the formula: (X/100) * Y.
• X is what percent of Y: To determine what percentage X is of Y, the formula is: (X/Y) * 100.
• X is Y% of what number: If you know that X is Y percent of a certain number, you can find that number using: X / (Y/100).
• Percentage Increase: The formula for percentage increase from a starting value (A) to an ending value (B) is: [(B - A) / A] * 100.
• Percentage Decrease: The formula for percentage decrease from a starting value (A) to an ending value (B) is: [(A - B) / A] * 100.

Real-World Applications:

Percentages are used in various contexts, including:

• Finance: Interest rates, investment returns, profit margins.
• Retail: Discounts, sales tax, markup.
• Statistics: Representing data, calculating probabilities.
• Health: Body fat percentage, changes in medical indicators.
• Education: Test scores, grading systems.