Calculating Percentages

Percentages are used when calculating a variety of things, from tax, to mark-up, to material allowances.

To perform this task, you must remember that:

• To convert a percentage to decimal, divide by 100 or move the decimal to the left two times
• To convert a decimal to a percentage, multiply by 100 or move the decimal to the right two times.

Example Calculating Percentages Using Decimals

Calculate a 5% increase in a length of 4400 m.

Convert 5% to a decimal:

Multiply the decimal by the length:

Add the length to the original length for a total length:

Example Calculating Percentages Using the Percent Button

Calculate 11% tax on a bill of $78.95

Use the following keystrokes:

$78.95 + 11   =

The answer is $87.63.

The percent button automatically converts a number to percent.  When the percent button is pressed, the percentage amount is displayed.  When the equal button is pressed the total amount (original plus percentage) is displayed.

When calculating a discount, press “-“ instead of “+”