Percentage increase and decrease

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

Percentage increase and decrease

a. 0,2 x 525 = 105

You will pay 105 euro more per week

b. 525 + 105 = 630

In the high season you will pay 630 euro per week

old price

increase

new price

old price

increase

new price

1.031 x 223 = 229,913

A year later there are 230 pupils in the second grade

Percentage increase

1. Add the percentage we are increasing by to 100%

(We add it on to 100% because we are increasing the original value.)

2. Convert to a decimal

3. Multiply the original amount by the decimal

old price

Decrease

new  price

old price

Decrease

new  price

Percentage decrease

1. Subtract the percentage we are decreasing by from 100%

(We subtract it from 100% because we are decreasing the value and 100% represents the original value)

2. Convert to a decimal

3. Multiply the original amount by the decimal

Daniel has £3600. He spends 27.5% of his money. How much does he have left?