1

Name

3

Group

Percentages

What does â€œper centâ€? mean? It means divided by 100, like this circle. So when it says what is 50% of 200? You have to divide 200 by 100 and then multiply by 50.

5

Starting at the arrow, colour 25 segments in red, 25 in blue and 25 in green.

0%/ 100 %

25 %

75 %

50 %

What do you notice about these 4 segments ? 7

Using what you have worked out from the previous page how will you answer the following questions? How did you work this out?

What is 50% of 10?

How did you work this out?

What is 25% of 20?

How did you work this out?

What is 75% of 12?

How did you work this out?

What is 25% of 16?

How did you work this out?

What is 50% of 10?

9

At the start we said that to find a percentage of something you divide by one hundred then multiply by what you want. You might think that dividing by hundred would be hard but it isnâ€™t. You just move the decimal point to the left, once divides by 10, twice by 100. Divide 20 by 10

20

.00

becomes 2.00

Move the decimal point 1 place to the left. (BTW that would be 10%) Divide 200 by 100

200

. 0 0 becomes 2

Move the decimal point 2 places to the left. That finds 1%. So if you want to find 40% of 200 multiply 2 by 40 = 80. 13% of 200 multiply 2 by 13 = 26 and so on.

Show your working

What is 1% of 250 ?

24%?

What is 1% of 300 ?

15%?

What is 1% of 20 ?

21%?

What is 1% of 500 ?

20%?

What is 1% of 75 ?

10%?

What is 1% of 40 ?

25%?

What is 1% of 450 ?

30%?

What is 1% of 60 ?

5%?

What is 1% of 150 ?

9%?

What is 1% of 100 ?

15%?

What is 1% of 25 ?

20%?

What is 1% of 450 ?

35%?

What is 1% of 250 ?

45%?

What is 1% of 250 ?

75%?

What is 1% of 250 ?

55%?

What is 1% of 250 ?

65%?

11

You can use a calculator to solve the following. A coat costs £20, but then we have to add on 20% VAT. How much will it cost in total? How did you work this out?

A meal in the restaurant cost £25 but they add a 10% service charge. How much do you have to pay? How did you work this out?

You book a flight to Paris for £80 but 5% airport tax has to be added, how much has to be paid? How did you work this out?

A cap costs £20, but it is reduced by on 10%. How much will it cost in total? How did you work this out?

A shop is selling dvds for £10 but if you buy 4 there is a 20% reduction. How much do you have to pay? How did you work this out?

You book a flight to Paris for £80 but there is a sale on with 5% off, how much has to be paid? How did you work this out?

13

While we are using a calculator here is a short cut for finding a percentage. To find 35% of 250 enter 250 into the calculator, enter x and then .35 . Press = and you should get the answer 87.5. Clear this. Now enter 250, รท by 100 to find 1% and then multiply by 35 to find 35%, what is your answer? Use the shortened method to find the following percentages and write down your keystrokes. For example: 45% of 350 = 157.5 Keystrokes 350 x .45 = 50% of 270 = Keystrokes 75% of 300 = Keystrokes 33% of 200 = Keystrokes

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