Percentage

Percentage

Cluster 7

Monday 26th April 2021

Learning objectives

• Student understand the concepts about fractions and decimals

• Student understand the forms of percentage as fractions and decimals

• Student understand the real world problem related to percentages

Timeline

• 08.30 - 09.15 course 1

• 09.15 - 09.30 break

• 09.30 - 10.15 handout

• 10.15 - 10.30 break 2

• 10.30 - 11.00 course 2

• 11.00 - 12.00 lunch break

• 12.00 - 13.30 handout

What we've learned so far?

• How to convert from fraction to percentage (and vice versa). Example: 4/5 = 80% and 35% = 7/20

• How to convert from decimal to percentage (and vice versa). Example: 0.12 = 12% and 87% = 0.87

Course 1

Expressing one Quantity as Percentage of Another

Example:

Total population = 5076700

Singaporeans = 3230700

Percentage of Singaporeans = 3230700 / 5076700 × 100% = 64%

Example 3

Multiple Choice

There are 45 male teachers and 75 female teachers. Find the percentage of male teachers

• 45/75

• 45/120

• 37.5%

• 60%

Multiple Choice

There are 45 male teachers and 75 female teachers. Find the percentage of female teachers

• 75/45

• 75/120

• 62.5%

• 166.7%

Percentage of male teacher of the female teacher is different than

Percentage of male teacher of the total teacher

Fill in the Blank

Find the value of the following:

20% of $13.25

(write your answer in two decimal places)

Fill in the Blank

Find the value of the following:
  $$15\ \frac{3}{4}\%$$ of $640

Fill in the Blank

Find the value of the following:
 2500% of $4.60

Practice now 4 (8 min.)

Write your complete steps in your notebook.

Multiple Choice

What is your answer for the 1st problem?

• 45 students

• 1455 students

Multiple Choice

What is your answer for the 2nd problem?

• 639

• 729

• 441

Multiple Choice

• True, The percentage of people passed the entrance test is higher in 2011 than 2012

• False! The percentage of people passed the entrance test is higher in 2012 than 2011

Practice now 5 (5 min.)

Write your complete steps in your notebook.

Multiple Choice

Which village had a higher percentage?

• Village A

• Village B

Handout

Do exercise 8A from text book, for all basic level

Course 2

Percentage Change

The change in the value of an item can be expressed as a percentage increase or decrease in the original value.

Example:

A man has an increase of his salary by 5%. His original salary is $100. This means, his final salary by percentage is 105%.

And his final salary is

105% × $100 = $105

The increase of his salary is $105 - $100 = $5.

Percentage Change

On the other hand, a decrease of 5% means his final salary by percentage is 95%

His final salary is

95% × $100 = $95

The decrease of his salary is $100 - $95 = $5.

Key Concept!

(write in your notebook)

Percent Change

https://www.youtube.com/watch?v=5nZEUpZX_P0

Fill in the Blank

What is your answer for problem 1a ?

Multiple Choice

What is your answer for problem 1b (i) ?

• 66.7%

• 0.667%

• 40%

• 0.4%

Multiple Choice

What is your answer for problem 1b(ii)

• 50%

• 100%

• 200%

Fill in the Blank

What is the result when 32 is decreased by 25%?

Multiple Choice

A new car costs $127,000. After one year, its value is $119,380. Find the percentage decrease in the value of the car!

• 0.06%

• 0.6%

• 6%

Practice now 7 (10 min.)

Write your complete steps in your notebook

End of the class

Upload your notebook from today's course.

See you next week.