Percentages

Conversion between % Fractions and Decimals

Percentages using a calculator

Percentage rise (Increase)

Percentage fall (Decrease)

Percentage Increase / Decrease

Percentage Profit / Loss

One quantity as a Percentage of another

Percentages

Learning IntentionLearning Intention Success CriteriaSuccess Criteria

1.1. To understand the term To understand the term percentage.percentage.

1. To explain what the term percentage means and how it is connected to fractions and decimals. 2.2. Understand connection between Understand connection between

percentages, fractions and percentages, fractions and decimals.decimals.

PercentagesPercentages

It is common to express fractions using a denominator of a 100

means 7 %

31 out of a 100

7 out of a 100

means 31 %

Q. Write down the following as a fraction and a decimal.

27%

PercentagesPercentages

27100

27 100 0.27

15%15100

15 100 0.15

2%2

100 2 100 0.02

Convert these percentages to fraction and simply

PercentagesPercentages

15

20100

20%

34

75100

75%

35

60100

60%

Covert these fractions to percentages

PercentagesPercentages

110

1 10 100 10%

320

3 20 100 15%

45

4 5 100 80%

Sandra got 15 out of 20 in an maths exam.What percentage is this.

PercentagesPercentages

1520

15 20 100 75%

Franchesca got 45 out of 60 in her Maths examand Michael got 21 out of 30 in an English exam.Who got the best result.

PercentagesPercentages

4560 45 60 100 75%2130 21 30 100 70%

Franchesca has the best result.

Starter Questions

75200

1. Calculate 1200 300

2. Simplify

3. Find of 65

4. Find highest number that divides both 14 and 35 without leaving a remainder.

110

Percentages

Learning IntentionLearning Intention Success CriteriaSuccess Criteria

1.1. To know how to calculate a To know how to calculate a percentage using a calculator.percentage using a calculator.

1. To explain how to calculate a percentage of a quantity using a calculator.

2.2. Show working.Show working.

Remember money 2 decimal places

Q. Find 17% of £450

PercentagesPercentagesof

means multiple

17450

100

17 100 450

£ 76.50

Remember !! money 2 decimal places

Q. Find 4% of £70

PercentagesPercentagesof

means multiple

470

100

4 100 70

£ 2.80

Percentage Increase

Learning IntentionLearning Intention Success CriteriaSuccess Criteria

1.1. Understand terms increase for Understand terms increase for percentages.percentages.

1. To explain some simple increases in percentages using shop prices.

2.2. Calculate simple increases in Calculate simple increases in percentages.percentages.

Example 2Example 2

The total hours of sunshine in June was 260.The total hours of sunshine in June was 260.The total for July was 5% higher than June..The total for July was 5% higher than June..What is the total hours of sunshine in July.What is the total hours of sunshine in July.

260 100 5 = 13

PercentageIncrease / Decrease

260 13 = 273July Total Hours =

Example 1Example 1

In a sale the cost of a jumper is reduced by 10%.In a sale the cost of a jumper is reduced by 10%.What is the sale price of the jumper.What is the sale price of the jumper.

35 100 10 = £3.50

Percentage Fall (decrease)

Original Price£3535 3 50 = £31.50.Sale Price =

Learning IntentionLearning Intention Success CriteriaSuccess Criteria

1.1. To understand how to express To understand how to express ““A” as a percentage of “B”.A” as a percentage of “B”.

1. To understand how to express “A” as a percentage of “B”.

2.2. Solve problems in context.Solve problems in context.

Calculating PercentagesCalculating Percentages

Calculating PercentagesCalculating Percentages

Linda scored 45 out of 100 in a Maths test.Write her score as a fraction in it simplest form ?

Fraction = 45100

9=

20

What was her percentage score ?45 %

Calculating PercentagesCalculating Percentages

My council tax has gone up by £60. It was £300 before the increase.Calculate the council tax increase as a percentage ?

% Increase60

300100

60=

300 =20%

Increase = £60

Calculating PercentagesCalculating Percentages

My car has decreased in value to £3000. Before the decrease it was valued at £5000.Calculate the decrease as a percentage ?

% decrease20005000

1002000

=5000

=40%

Increase = 5000 – 3000 = £2000

Learning Intention Success Criteria

1. To know the meaning of the terms PROFIT and LOSS in terms of percentages..

1. To understand theterms profit and loss in terms of percentages.

2. Apply knowledge to calculations.

Profit and LossProfit and Loss

Profit and Loss

Profit : When you sell something for MORE than you bought it.

Loss : When you sell something for LESS than you bought it.

PROFIT = Selling Price – Buying Price

LOSS = Buying Price – Selling Price

Profit and Loss

If I buy a iPod for £200 and sell it for £220.What is my percentage profit.

£220 - £200 = £20I have made a PROFIT of

% increase = 20200

20= 100

200 =10%

Profit and Loss

I bought a bunch of flowers for £6.00 and tried to sell them for a profit. But I found it difficult to sell them. I sold them for £4.00

before they went off.

I made a LOSS of £6.00 - £4.00 = £2.00

% decrease = 2.006.00

2.00= 100

6.00

1=33 %

3

Calculating PercentagesCalculating Percentages

Example 1 : Daniel was paid £20 per week. He got a wage rise to £22 per week.

What was his percentage increase in pay ?

% increase = increase

original pay2

= ×10020 =10%

Actual Increase = £22 - £20 = £2A

B

Percentage Increase / Decrease

Calculating PercentagesCalculating Percentages

Example 2 : A house in Barlanark bought for £40 000 in 2001 was sold last week for £50 000. Calculate the percentage increase in value?

% increase = increase

original price10 000

= ×10040 000 =25%

Actual Increase = £50 000 - £40 000= £10 000

A

B

Percentage Increase / Decrease