How to calculate by percentage
In many aspects of life, we come across situations requiring us to calculate by percentage. From discounts and tax rates to calculating salary raises, percentages are an essential mathematical concept in our daily lives. In this article, we’ll explore the basics of percentages, how to calculate them, and apply them in various real-life scenarios.
Understanding Percentages
A percentage represents a ratio expressed as a part of 100. It’s denoted using the percent symbol (“%”). Essentially, it tells us how many parts out of 100 are contained in a given value. For instance, if someone scores 75% on an exam, they got 75 out of every 100 possible points.
Basic Percentage Calculation
To calculate a percentage, follow these simple steps:
1. Divide the portion (part) by the total (whole).
2. Multiply the result by 100 to convert it to a percentage.
3. Add the percentage symbol (“%”) to your answer.
Here’s a simplified mathematical formula:
Percentage = (Part / Whole) × 100
Let’s take an example: To find out what percentage 50 is of 200:
Percentage = (50 / 200) × 100
Percentage = 0.25 × 100
Percentage = 25%
Calculating Percent Increase or Decrease
In business or personal finance management, you may need to calculate the percent increase or decrease between two values. Here’s how:
Percent Change = [(New Value – Old Value) / Old Value] × 100
For instance, if a product’s price increases from $20 to $25:
Percent Change = [(25 – 20) / 20] × 100
Percent Change = [5 / 20] × 100
Percent Change = 0.25 × 100
Percent Change = +25% (indicates an increase)
Reverse Percentage Calculation
In some cases, you might need to find the original value before a percentage change occurred. To do this, use the following formula:
Original Value = New Value / (1 + Percent Change)
For example, if you bought an item for $60 that was marked as 20% off:
Original Value = 60 / (1 + (-0.20))
Original Value = 60 / 0.80
Original Value = $75
Converting Between Fractions, Decimals, and Percentages
Sometimes, you may need to convert between different number formats. Here’s a quick guide:
1. Fraction to Percentage: Multiply the fraction by 100.
2. Decimal to Percentage: Multiply the decimal by 100.
3. Percentage to Fraction: Divide the percentage by 100.
4. Percentage to Decimal: Divide the percentage by 100.
Conclusion
Understanding how to calculate percentages is vital in various aspects of life, spanning education, shopping, business management, finance, and much more. By mastering these basic calculations and knowing when to apply them, you’ll be well-equipped to tackle any percentage-related problem with ease!