PERCENTAGES

A percentage (from Latin per centum "by a hundred") is a number or ratio expressed as a fraction of 100.​

​Percentages as fractions

The term per cent means ‘per hundred’. The symbol for per cent is %. For example, 7% means 7 out of 100.

​

Whether a percentage is a whole number, a mixed number, a proper fraction, or a decimal, it can be expressed as a fraction.

​

​To convert a whole number percentage into a fraction, write it over 100 and simplify.

​Percentages as decimals

​Percentages can be expressed as decimals.

To convert a percentage to a decimal, divide the percentage by 100 by moving the decimal point two spaces to the left.

Subject | Subject

Multiple Choice

Change 80% to a decimal

• 8.0

• 0.08

• 0.8

Multiple Choice

What fraction is equivalent to 25%?

• 1/3
• 1/4
• 1/5
• 1/8

Multiple Choice

change 25% to a decimal

• .25
• .2
• 2.5
• .025

Multiple Choice

Find 25% of 200

• 25
• 50
• 100
• 5

Multiple Choice

Change 247% to a decimal

• 24.7
• 2.47
• .247
• .0247

Multiple Choice

find 50% of 180

• 9
• .9
• 90
• 900

Multiple Choice

5% of 120 is 

• 5
• 12
• 6
• 10

​Changing fractions to percentages

To change a fraction to a percentage:

1. multiply by 100/1

2. Simplify if possible.

3. Add the percentage (%) sign.

Multiple Choice

Express $$\frac{11}{50}$$  as a percent.

• 220%

• 22%

• 50%

• 55%

Multiple Choice

Convert 2.75 to a percent.

• 275%
• 2.75%
• 27.5%
• .275%

Multiple Choice

James took a quiz and got 15 questions out of 20 questions right what was his grade percentage?

• 75%
• 50%
• 100%
• 15%

Multiple Choice

Of the students in 6th grade, 3/5 pack their lunch. What percent of students pack their lunch?

• 70%

• 66.7%

• 60%

• 54%

Multiple Choice

In a neighborhood 12/40 of the kids are in middle school. What percent is equivalent to the number of neighborhood kids in middle school?

• 35%

• 24%

• 30%

Multiple Choice

Convert to a percent:

0.35

• 35/100

• 0.035%

• 35%

• .35%

Multiple Choice

Convert to a percent

0.375

• 37%

• 37.5%

• .375%

• 37

Multiple Choice

Convert $$\frac{13}{20}$$  into a percentage.

• 13%

• 60%

• 65%

• 0.13

Multiple Choice

Write 0.55 as a percentage.

• 5.5%

• 555%

• 0.55%

• 55%

Percent Increase and Decrease

A percentage that tells us how much a quantity went up or down, expressed as a percentage of the starting amount.

The original amount corresponds to 100% and the new amount corresponds to more or less than 100%, depending on whether the situation involves an increase or decrease.

​

​1. We can use a double number line diagram to represent situations involving percent increase or decrease.

​

​2. We can calculate the percent increase or decreases of the original amounts to identify the new amount.

​Last year, Mrs. Melder's class raised $200 to buy books for the school. This year, her class raised 22% more. How much did her class raise this year?

​

​

​1. Find 22%of the original amount: .22 (200)

​2. Add the increase to the original amount.

Multiple Choice

20% discount on 85

• 60

• 65

• 68

• 70

Multiple Choice

Increase £350 by 12%...

• £392

• £308

• £42

• £408

Multiple Choice

Increase £2600 by 4%...

• £2704

• £2730

• £2756

• £2678

Multiple Choice

Decrease £2200 by 8%...

• £2024

• £1980

• £2002

• £2376

Multiple Choice

Decrease £220 by 20%.

• £170

• £176

• £200

• £44

Multiple Choice

Decrease £40 by 20%

• £9

• £21

• £32

• £20

Remember:​

% is a ratio that compares a number t0 100​.

Multiple Choice

1. How to find percentage change?

• $$\frac{Original\ Quantity}{Change}\times100\%$$

• $$\frac{Change}{Original\ Quantity}\times100\%$$

• $$\frac{Decrease}{Increase}\times100\%$$

• $$\frac{Increase}{Decrease}\times100\%$$

Multiple Choice

Find the percentage change in the following price reduction:

£320 to £272

• 48%

• 17.6%

• 15%

• 85%

Multiple Choice

Find the percentage change in the following price increase:

£64 to £160

• 250%

• 150%

• 220%

• 185%

Multiple Choice

Find the percentage change in the following price increase:

£1250 to £1300

• 4%

• 2%

• 5%

• 10%

Multiple Choice

Find the percentage change in population of a school when 500 students becomes 475 students

• 5% increase

• 5% decrease

• 20% decrease

• 25% decrease

Multiple Choice

A computer accessories shop increased the price of one of its printers from £80 to £100. Find the percentage increase in price.

• 0.25
• 20
• 25
• 0.20

Multiple Choice

There were 200 customers yesterday, and 240 today. what is the percentage changes?

• 10%

• 15%

• 20%

• 25%

Profit

• Profit is earned when the selling price is greater than the cost price.

• You can calculate percentage profit as a percentage of the cost price or the selling price, but it is most common to use the cost price.

• Profit = selling price – cost price

Loss

• A loss is incurred when the selling price is less than the cost price.

• Loss = cost price – selling price

Find the price from percentage profit

• Terry buys goods at a cost of $4.50 each. What must his selling price be in order to make a 20% profit?

• Terry must sell the goods at $5.40 each to make a 20% profit.

Multiple Choice

What is the profit percent if a shopkeeper buys a football for $12 and sells it for $15?

• 80%

• 25%

• 20%

• 50%

Multiple Choice

What is the percentage profit if Tony buys a watch for $50 and sells it for $60?

• 20%
• 25%
• 16.6%
• 16.7%

Multiple Choice

If James sells his car for $1,000 and bought it for $2500. What is the percentage loss made on the car.

• 15%
• 10%
• 60%
• 150%

Multiple Choice

If James sells his car for $1,000 and bought it for $2500. What is the percentage loss made on the car.

• 15%
• 10%
• 60%
• 150%

Multiple Choice

Ben bought a hoverboard for S45000 and sold it for S34000. Is it a profit or a loss?

• Profit

• Loss

• Don't know

Multiple Choice

What is the percentage profit if Tony buys a watch for $50 and sells it for $60?

• 20%
• 25%
• 16.6%
• 16.7%

Multiple Choice

The term used to describe money gained after a sale.

• cost price
• selling price
• profit 
• loss

Multiple Choice

state true or false:profit=selling price[s.p]-cost price[c.p]

• true

• false

• both options

• can't tell

Multiple Choice

What is formulae to calculate profit percentage?

• Profit% = $$\frac{profit}{C.P.}\times100\%$$

• Profit% = $$\frac{C.P}{profit}\times100\%$$

• Profit% = $$\frac{profit}{S.P.}\times100\%$$

• $$\Pr ofit\%=\frac{profit}{C.P.}$$

Multiple Choice

What is condition of loss?

• M.P. > S.P.

• S.P. > C.P.

• C.P. > S.P.

• S.P. > M.P.

Multiple Choice

What is the percentage profit if a Shopkeeper buys in a football for 12 euro and sells it for 16euro?

• 75%
• 33%
• 25%
• 50%