# Understanding  Percentage

Percentage is a term used to describe a portion of something in relation to the whole. It is represented using the symbol % and typically expresses a value as a fraction of 100. In other words, a percentage is a way of expressing how much of something there is, in relation to the total amount available.

## What is Percentage Used For?

Percentage has many uses in our daily lives. It is commonly used to calculate interest rates, compound interest, investment returns, and discounts. It is also used in statistics and other fields that require the representation of parts within a whole.

## How to Calculate Percentage

To calculate percentage, you divide the part by the whole and multiply by 100. For example, if you want to calculate what percentage of an apple pie you ate (2/8 slices), you would divide 2 by 8 and then multiply by 100. The result would be that you ate 25% of the apple pie.

## Interest Rates and Percentage

Interest rates are typically expressed as a percentage rate over a specific period. For example, an interest rate of 5% per year means that for every \$100 invested, \$5 will be earned in interest over one year.

## Compound Interest and Percentage

Compound interest is when interest is added to the principal amount, creating an ever-growing balance that earns more interest as time goes on. The amount earned increases exponentially with each passing year. The formula for calculating compound interest involves using percentage values.

## Investment Returns and Percentage

Investment returns also rely heavily on percentage values. They represent the profit or loss made on an investment related to its initial cost or value. The calculation is based on the difference between the final value and initial cost using a percentage increase or decrease.

## What are Some Common Percentages?

Some common percentages include:

• 50% - half
• 25% - one quarter
• 10% - one tenth
• 5% - one twentieth
• 1% - one hundredth

## How to Convert Between Fraction, Decimal, and Percentage

Converting between fraction, decimal, and percentage is a simple process. To convert from a decimal to a percentage, you multiply the decimal by 100. To convert from a percentage to a decimal, you divide the percentage by 100. To convert from a fraction to a percentage, you first convert the fraction to a decimal and then multiply by 100.

## Final Thoughts on Percentage

Percentage is an essential concept that we use in many different areas of our lives. It allows us to express how much of something exists in relation to the whole. By understanding how to calculate percentages and use them in different scenarios, we can make better decisions about investments, savings, and many other financial decisions.

### References:

• Bluman, A.G. (2014). Elementary Statistics: A Step by Step Approach.
• Lial, M.L., Greenwell,R.N., & Ritchey,N.P. (2013). Calculus with Applications.
• Larson,R.E., & Edwards,B.H. (2013). Calculus(10th Ed.). Wiley.
• Guichard,D.(2005). Calculus I.
• Khan,Academy.(2021). Mathematics for Machine Learning Specialization (online course).