Contents

Percentages

Percentage Change

Percentages

A percentage is a fraction in which the denominator is equal to 100.

Percentages

Example 1

For example,100

7%7

Change each of the following into percentage.

(a) 0.8325

12(b)

Solution :

%83%10083.083.0 (a)

%48%10025

12

25

12(b)

When an original value is changed to a new value, the percentage

change of the value can be measured in the following way.

Original – New = X

original 100

To find a change…you subtract!!!

Percentage Change

Percentage Change

Example 1

Solution :

%10060

6048

change Percentage

Peter’s weight decreases from 60 kg to 48 kg. Find the percentage change of his weight.

Percentage decrease of weight is 20%.

Discount is a price deduction from a marked price in purchasing.

Discount

Example 2

Solution : %100

4500

30004500

rate discount The

The marked price of a washing machine is $4500. If the selling price is $3000, find the discount percentage.

%3

133

Percentages1Examples 3

A rose bush grew from 20 inches to 40 inches. Is that a percent increase or decrease?

How do we set up our proportion?

Original and new = x

original 100

40 - 20 = x

20 100

20 x

20 100

100% increase

Percentages1Example 4

Jim received a raise at work. His original salary was 10.00 and hour. His new salary is 12.00 an hour. What percent did his salary change?

Is this a percent increase or decrease?

How do we set up our proportion?

12.00 – 10.00 = x

12.00 100

Answer: close to a 17% increase