# Simple Problems on Percentages (Primary 5 and Primary 6)

**MATHEMATICS**

**FIRST TERM/F****IRST/WEEK/PRIMARY**** 6**

**SECOND TERM/WEEK 2/PRIMARY 5**

**THEME: NUMBER AND NUMERATION**

**TOPIC: PERCENTAGES**

Percentage means quantities divided into hundred parts.

**PERFORMANCE OBJECTIVES**

By the end of the lesson, the pupils should have attained the following objectives (cognitive, affective and psychomotor) and be able to:

1. recognise the idea (meaning) of percentages;

2. express numbers as a percentage of other numbers;

3. solve problems on percentage increase;

4. solve problems on percentage decrease;

5. find percentages of quantities

**ENTRY BEHAVIOR**

The pupils are required to already have learned ratio and proportions.

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

1. Source for correct data on HIV/AIDS.

2. Data chart on HIV/AIDS.

3. Charts with population figures.

**METHOD OF TEACHING – Choose a suitable and appropriate methods for the lessons.**

**Note – Irrespective of choosing methods of teaching, always introduce an activities that will arouse pupil’s interest or lead them to the lessons. **

**REFERENCE MATERIALS**

Scheme of Work

9 – Years Basic Education Curriculum

New Methods Mathematics Book 6

Champion Mathematics Book 6

All Relevant Material

Online Information

**CONTENT OF THE LESSON**

**LESSON ONE – IDEA OF PERCENTAGE **

Group’s/Pupil’s Activities 1 – Count the number of spaces on the chart

**Total number of spaces is 100.**

**Group 1 – Count the shaded and unshaped parts **

**Shaped parts, _____ and unshaded parts _____. **

**Group 2 – Count the shaded and unshaped parts **

**Shaped parts, _____ and unshaded parts _____. **

**Group 3 – Count the shaded and unshaped parts **

**Shaped parts, _____ and unshaded parts _____. **

**Teacher’s remark – Percentage means quantities divided into hundred parts. Each of the space presents a percentage. 2 spaces represent 2 percent and it’s written as 2% or 2/100 (as known as fraction) . This symbol (%) represents percentage. **

Pupil’s Activities 2 – Express the shaped and unshaded parts as percentage and fraction.

**Group 1, **

Shaded parts is 35% or 35/100

Unshaded parts is 65% or 65/100

**The same goes for group 2 and 3.**

Pupil’s Exercises/Assignments

Write these percentages aw fractions.

1. 70%

2. 54%

3. 18%

4. 25%

5. 44%

Write these fractions as percentages.

6. 51/100

7. 72/100

8. 42/100

9. 185/100

10. 1725/100

**LESSON TWO – EXPRESSING NUMBER OR QUANTITY AS A PERCENTAGE OF ANOTHER **

Teacher’s Activities – Guides pupils to follow the steps below when a number or quantity is to be expressed as a percentage of another.

**Teacher’s/Pupil’s Activities 1 – Express 40 as percentage of 80.**

= 40/80 x 100

= 1/2 x 100

= 100/2

= 50%

**Pupil’s Activities 2 – Express 20 as percentage of 50.**

= 20/50 x 100

= 2/5 x 100

= 2 x 20

= 40%

**Pupil’s Exercises/Assignments **

Express the first quantity as a percentage of the second:

1. 15 to 20

2. 18 months to 24 months.

3. 25 out of 100.

**LESSON THREE – PERCENTAGE INCREASE (ADDITION) AND DECREASE (SUBTRACTION) **

- Percentage increase

Teacher’s Activities – Guides pupils to follow the steps below when working on percentage increases or decrease.

Teacher’s/Pupil’s Activities 1 – Increase ₦15 000 by 10%

10% = 10/100

= ₦15 000 x 10/100

= ₦150 x 10

= ₦1500

10% increase is ₦15 000 + ₦1500

= ₦16 000.

**Teacher’s remark – You add, if it’s percentage increase and subtract, if it’s percent decrease.**

Teacher’s/Pupil’s Activities 2 – Decrease ₦15 000 by 20%

20% = 20/10

Therefore,

= ₦15 000 x 20/100

= ₦150 x 20

= ₦3 000

20% decrease is ₦15 000 – ₦3 000

= ₦12 000.

**Pupil’s Exercises/Assignments **

1. Increase ₦6 000 by 15%.

2. A new laptop cost ₦50, 000 is decreased by 10%. What is the new price?

**Lesson 4 is For Primary 6**

**LESSON FOUR – WORD PROBLEMS ON PROPORTION **

Teacher’s Activities – Guides pupils to follow the steps below when working on proportion.

Teacher’s/Pupil’s Activities 1

- Mr. Ola buys 50 bags of rice every month. If he plans to increase the quantity by 30%, how many bags will he buy?

30% = 30/10

Therefore,

= 50 x 30/100

= 5 x 3

= 15

30% increase is 50 + 15

= 65 bags.

Teacher’s/Pupil’s Activities 2

- A man bought a carton of milo at ₦5 500, 3 months ago. When she went again to the market to buy another carton, he discovered that the price has decreased by 15%. How much is the present price?

15% = 15/100

Therefore,

= ₦5 500 x 15/100

= ₦55 x 15

= ₦825

15% decrease is ₦5 500 + ₦825

= ₦6 325

Pupil’s Exercises/Assignments

- Transport fare was increased from ₦40 to ₦350, what is the percentage increase.
- House rent is ₦60 000 per annum. What rent must be charged to give 25% decrease?

**PRESENTATION**

To deliver the lesson, the teacher adopts the following steps:

1. To introduce the lesson, the teacher revises the previous lesson. Based on this, he/she asks the pupils some questions;

2. Guides pupils to express numbers as a percentage of another;

Pupil’s Activities – Express numbers as a percentage of another.

3. Guides pupils to calculate numbers expressed as a percentage of another;

Pupil’s Activities – Calculate numbers expressed as a percentage of another.

4. Guides pupils to calculate percentage increase and decrease;

5. Guides pupils to solve problems on percentage increase and decrease;

Pupil’s Activities – Solve problems on percentage increase and decrease.

6. Guides pupils to give more examples of everyday activities where percentage increase and decrease is needed;

Pupil’s Activities – Gives examples of everyday activities that require percentage increase.

7. Guides pupils to solve problems in quantitative aptitude on percentage increase or decrease.

Pupil’s Activities – Solves quantitative aptitude on percentage decrease.

**CONCLUSION**

- To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.

**LESSON EVALUATION**

**Pupils to:**

1. express given numbers as a percentage of another;

2. calculate given numbers expresses as a percentage of another;

3. calculate percentage increase of a given population growth;

4. calculate percentage decrease of a given population growth;

5. solves quantitative aptitude on percentage increase and decrease.