You currently have JavaScript disabled on this browser/device. JavaScript must be enabled in order for this website to function properly.

# ZingPath: Calculations with Percents

## Simple Interest             Searching for

## Calculations with Percents

Learn in a way your textbook can't show you.
Explore the full path to learning Calculations with Percents

### Lesson Focus

#### Simple Interest

Pre-Algebra

Students solve simple interest problems while visiting a bank.

### Now You Know

After completing this tutorial, you will be able to complete the following:

• Solve percent problems in contextual situations using the simple interest formula.

### Everything You'll Have Covered

In this Activity Object, students use the simple interest formula to solve percent problems involving investments and loans. Be sure to review the following pre-requisite concepts with the class before starting the Activity Object.

Simple Interest is the most basic kind of interest. When someone lends money to someone else, the borrower usually pays a fee to the lender. This fee is the simple interest. The amount of simple interest paid each year is a fixed percentage of the amount borrowed or lent at the start. It is just the amount of money paid on a loan. In general, it is charged for borrowing money for short periods of time.

• formula for simple interest - I = prt where I is the simple interest, p is the principal, r is the rate of interest, and t is the period of time
• percent and decimal equivalents - to convert a decimal to a percent, multiply by 100 and to convert a percent to a decimal, divide by 100For example, Convert 0.75 to a percent.0.75 � 100 = 75%
• solving equations - For example,Find the simple interest for 2 years at a rate of 6% on \$1,500. Solution:Step 1: Simple Interest = prt [Formula for simple interest]Step 2: = 1500 � 0.06 � 2 [Substitute p = 1500, r = 0.06, t = 2 Use 0.06 for 6%] Step 3: = \$180 [Simplify.] Step 4: The simple interest on \$1500 for 2 years is \$180

The following key vocabulary terms will be used throughout this Activity Object:

• interest rate - the rate in which an amount of money borrowed (or loaned) increases over time
• principal - the amount of money invested or borrowed
• simple interest - the interest calculated only on the principal regardless of the interest earned so far

### Tutorial Details

 Approximate Time 15 Minutes Pre-requisite Concepts formula for simple interest, interest rate, multiplication of decimals, percent and decimal equivalents, principal, simple interest, solving equations Course Pre-Algebra Type of Tutorial Problem Solving & Reasoning Key Vocabulary problems, rate, simple interest