Percentage increase and decrease

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 1

A survey found that out of 9,700 people, 5,345 prefer online shopping over in-store shopping. What percentage prefers online shopping?

55.1%

Starting task:

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

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 the "'new"percentage to a decimal or fraction

3. Multiply the original amount by the decimal

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

What?	Practice 2.2: make exercises: # 1 till 8 Page 68
Help?	- Book or Handouts or notes. -Group -Teacher
Ready?	Check your answers
Not done?	Homework

Now you try: