Intro to Percents

Percentage

• ​Finding the Percentage of a Quantity

• Finding the Whole

• Percentage Change

• Word Problems

Percentage

The percentage is a fraction or a ratio in which the value of the whole (denominator) is always 100. For example, if Sam scored 30% marks in his math test, it means that he scored 30 marks out of 100. It is written as 30/100 in the fraction form and 30:100 in terms of ratio. Here "%" is the symbol of percentage and is read as "percent" or "percentage". This percent symbol can always be replaced with "divided by 100" to convert it into a fraction or decimal equivalent.

Percentage

Examples of Percentage:

10% = 10/100 ( = 1/10 (or) 0.1)

25% = 25/100 ( = 1/4 (or) 0.25)

12.5% = 12.5/100 ( = 1/8 (or) 0.125)

50% = 50/100 ( = 1/2 (or) 0.5)

Percentage

Multiple Choice

Express 5/20 as a percentage

• 20%

• 25%

• 30%

• 10%

Multiple Choice

What percentage of the figure is unshaded?

• 40%

• 50%

• 70%

• 60%

Multiple Choice

What is ½ as a percentage?

• 10%

• 25%

• 50%

• 75%

Multiple Choice

What is 1/10

as a percentage?

• 1%

• 5%

• 10%

• 20%

Percentage

Multiple Choice

CHANGE THE FOLLOWING INTO PERCENT.

5/20

• 20%

• 25%

• 30%

• 35%

Multiple Choice

CHANGE THE FOLLOWING INTO PERCENT:

8/25

• 8%

• 36%

• 32%

• 25%

Percentage

Finding Percentage When the Total is 100

When we have two or more values that add up to 100, the percentage of those individual values to the total value is that number itself. For example, Sally bought tiles of three different colors for her house. The details of the purchase are given in the following table.

Percentage

Finding Percentage When the Total is NOT 100

Since the total number of items adds up to 100, the percentages could be easily calculated as shown above. What if the total number of items does not add up to 100? Let us see.

For example, Emma has a bracelet that is made up 8 red beads and 12 blue beads. Here, the total number of beads is 8 + 12 = 20 (which is not equal to 100). In this case, the percentages can be calculated as shown in the table below (using the unitary method).

Percentage

Percentage

Converting Percentage to Fractions.

For Example:

Question- Convert 30% to Fractions.

Solution- 30/100= 3/10

~We will divide 30/100 so that it can be get converted into fractions.

~Basically, we have to just divide the percentage by 100.

Fill in the Blank

Q3. Convert 20% to Fractions. (Just writes the answer directly)

Fill in the Blank

Q4. Convert 650% to Fractions. (Just writes the answer directly)

Converting Decimals into Percentage.

For Example:

Question- Convert 0.3 in Percentage.

Solution- 0.3*100= 30%

~We will multiply 0.3 by 100, so that it can be get converted in percentage form.

~Basically, just multiply the decimal form by 100 to get your answer in Percentage form.

Fill in the Blank

Q5. Convert 7.5 into %. (Just writes the answer directly)

Fill in the Blank

Q6. Convert 0.5 into %. (Just writes the answer directly)

Converting Percentages into Decimals.

For Example:

Question- Convert 30% into Decimals.

Solution- 30/100= 0.3

~We will multiply 30 by 100, so it can be get converted in percentage form.

Fill in the Blank

Q8. Convert 99% to decimals. (Just writes the answer directly)

.

Multiple Choice

David says that 1/4 is greater than 40%.Is he right?

• yes

• no

Multiple Choice

How would you say 100% in other words?

• one whole

• one quarter

• three quarters

• one half

Multiple Choice

In a class of 30 children.60% are girls.How many girls are in the class?

• 12

• 19

• 18

• 9

Multiple Choice

Write 164 as a percentage of 200

• 82%

• 16.4%

• 32.8%

• 80%

Multiple Choice

Olivia completed 85% of the Math questions. She still has 6 questions left. How many questions were there in total?

• 32

• 45

• 50

• 40

Multiple Choice

A mixture contains 8 L of water and 42 L of milk. What is the percentage of water in the mixture?

• 19.0%

• 16%

• 80.1%

• Not listed

Multiple Choice

There are 20 questions in a test and you get 75% correct. How many questions do you get right ?

• 15

• 12

• 10

• 5

Multiple Choice

You are shopping for a new shirt, and you have narrowed your decision down to two. Both shirts are $35, and both are on sale. Shirt A is 25% off. Shirt B is $10 off. Which shirt is the better deal?

• Shirt A

• Shirt B

• The discount is the same.

• Well, it really depends on which one she likes more.

Multiple Choice

What is 10% of $250

• $2.50

• $25

• $250

• $2500

Multiple Choice

What is 25% of 2 hours?

• 45 minutes

• 30 minutes

• 0.3 hours

• 0.5 minutes

Multiple Choice

Convert 0.81 to a percent

• 0.81%

• 0.18%

• 8.1%

• 81%

Multiple Choice

What fraction is equivalent to 25%?

• 1/3

• 1/4

• 1/5

• 1/8

Multiple Choice

My class size has increased by 35% this year. I had 20 students last year, how many do I have now?

• 23

• 25

• 27

• 29

Multiple Choice

The number of kids in a playground grew by 10% in thirty minutes.  If there are 77 kids in the park now, how many were there before?

• 70

• 71

• 72

Multiple Choice

Find 25% of 200

• 25

• 50

• 100

• 5

Multiple Choice

Change .04 to a percent

• 40%

• 400%

• 4%

• .4%

Multiple Choice

find 17% of 23

• 3.91

• .391

• 39.1

• 391

Multiple Choice

Identify whether the given amount increased or decreased.

From 45 ft to 92 ft.

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

From 94 miles to 34 miles.

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

From 188 m to 42 m.

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

Olivia scored 82 points on the first math test of the year. On the second math test, she scored 78 points

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

The average cost of a gallon of gas during July was $2.45. The average cost of a gallon of gas during August was $2.78.

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

There were 134 people in attendance at the school football game last Friday. This week there were 246 people in attendance at the school football game.

• Increase

• Decrease

Multiple Choice

Identify whether the given amount increased or decreased.

On Monday, Jake could lift 25 lbs. One month later he could lift 45 lbs.

• Increase

• Decrease

Multiple Choice

Calculate 5% of 140

• 14

• 28

• 7

• 70

Open Ended

A T-shirt costs Php 500. You get 10% off in the sales. How much do you pay for the T-shirt ?

Multiple Choice

There are 20 questions in a test and you get 75% correct. How many questions do you get right ?

• 15

• 12

• 10

• 5