# 8.1.6 Calculator Exploration: Percentage Conversions

The calculator can be accessed on the left-hand side bar under Toolkit.

In this exploration, you will use the calculator for percentage conversions.

## To Write a Percentage as a Fraction or a Decimal

Remember that the percent sign means “out of one hundred.” So, 5% means , and this is how it is entered on the calculator.

Enter 5% as on the calculator, and click the equals sign, or hit Enter on your keyboard.

The key sequence is

The calculator gives the fraction in its reduced form with the decimal equivalent.

### Activity: Converting Percentages to Fractions

Try writing these percentages as fractions and as decimals.

(a) 88%

#### Comment

Clear the last calculation before you start, and remember that % means “out of one hundred.”

#### Answer

(a) Entering 88% as 88 divided by 100 gives 0.88, so .

(b) 250%

#### Answer

(b)

## To Write a Decimal Number as a Percentage

To write a decimal number as a percentage, multiply the number by 100%. The calculation is quite easy to do without the calculator because you can move the decimal point two places to the right. For example, 0.8 becomes . Let’s check that the calculator does the same. Enter the calculation . The calculator gives the answer 80.

**Remember that you must include the % sign when you quote the
answer.**

### Activity: Converting Decimals to Percentages

Use the calculator to write these decimal numbers as percentages:

(a) 0.28

#### Answer

(a) To convert 0.28 to a percentage, multiply by 100%. Using the calculator, multiply by 100, and then attach the % sign when you write the answer down, as follows: .

*Note:* We do **not** use the percent key
when converting a decimal to a percentage. When you use
the percent key, it is converting the value to its
decimal equivalent. Here, you are just trying to find
the value that belongs in front of the percent sign.

(b) 1.052

#### Answer

(b) . (Did you remember to attach the % sign when you wrote the answer down?)

(c) 0.006

#### Answer

(c) .

8.1.5 Converting