2at 6.1 calculations with percentages

• Wiskunde
• Middelbare school
• vwo
• Leerjaar 2

Percentages

what percentage is 12 out of 57

1. 21
2. 21,1
3. 21,05263158
4. 271,4

lesson goals

• I know how ratio tables work.
• I can calculate the New Price.
• I know how to use the factor.
• Assignment for groupwork (criteria)

In 2020 the season card of arsenal cost 1200 pounds and this year it has increased by 10%. Calculate the NP?

Zandbelt wants to buy a laptop but he cant afford to pay 650 Euro. After negotiating he got a discout of 15%. Calculate the NP?

Lesson goals

I can calculate increase and decrease with percentages

I know the difference between absolute and relative increase

Describe in your own words what increase and decrease are

Pascal college had 1278 students in 2016. In 2017 there were 3,6% more. Calculate how many students went to Pascal college in 2017.

1. 46
2. 46,01
3. 1324,008
4. 1324

Describe in your own words the difference between increase and percentage increase.

Calculating percentage increase

Percentage increase = 

Example: The price of a €16 book is increased to €18. Calculate the absolute and relative price increase.

Absolute=18 - 16 = €2

Relative= 2/16 x 100 = 12,5%

​OLD​​(increase)​​⋅100

The number of students in a school increased from 1150 to 1223. Calculate the relative increase.

1. 6,3%
2. 94,0%
3. 6,0%
4. 73

What do you think the formula for calculating percentage decrease will be?

Homework

Make paragraph 6.1.

Ex. 2 is a test exercise. If you do it correctly, you can skip ex. 3 and 4.

Describe in your own words the difference between relative and absolute increase.