### What is simple interest?

**Interest **is paid for borrowing money. There are different ways of calculating interest. **Simple interest **is a fixed percentage of the amount borrowed and is calculated on the original amount. The formula used for simple interest is I =Prn where I is the interest, P is the amount initially borrowed, r is the rate of interest and n is the number of time periods borrowed for. This post will help you understand simple interest in Prelim Standard Math.

### Simple interest broken down

The video below helps explain concepts you might have been taught in your junior years and how they apply to the Prelim Standard Math course.

### How to calculate simple interest

The following videos explain how to approach a variety of simple interest problems.

##### Part 1: How to calculate simple interest

##### Part 2: How to calculate yearly interest using the simple interest formula

##### Part 3: How to calculate monthly interest

##### Part 4: How to calculate interest on credit card statements

##### Part 5: How to rearrange the simple interest formula to find unknown values