# Ratio and Percentages (Primary 5)

**MATHEMATICS **

**SECOND TERM**** **

**WEEK 1 **

**PRIMARY 5 **

**THEME – NUMBER AND NUMERATION **

** PREVIOUS LESSON – First Term Examination Links For Primary Schools**

**TOPIC – RATIO AND PERCENTAGES **

**LEARNING AREA**

1. Introduction to Ratio

2. Ratio in its Lowest

3. Percentages

4. Word problems

**PERFORMANCE OBJECTIVES **

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

1. recognise the idea of ratio.

2. simplify ratio in its lowest term.

3. express numbers as a percentage of another.

4. solve problems involving ratio.

**ENTRY BEHAVIOUR **

- Comparisons

**INSTRUCTIONAL MATERIALS**

The teacher will teach the lesson with the aid of:

1. Number of pupils in the class.

2. Different shapes with different colors

**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**

1. Scheme of Work

2. 9 – Years Basic Education Curriculum

3. Course Book

4. All Relevant Material

5. Online Information

**CONTENT OF THE LESSON **** **

**LESSON 1 – INTRODUCTION **

Teacher’s/Pupil’s Activities 1 – Ask a boy to count the number of boys in the class and the girls to do the same. Then, note the results on the board.

For example,

Boys – 24

Girls – 30

**Pupil’s Activities 2 – Ask them to compare the number of boys and girls together. **

The number of girls is more than the number of boys.

Boys < girls

Girls > boys

**Teacher’s remark – Comparing the number of boys and girls together is called ratio. **

Aratiois a way to show a relationship or compare two numbers of the same kind. Ratio is useratiosto compare things of the same type.

The ratio of boys and girls is written as –

1. boys : girls, this means ratio of boys to girls

2. girls : boys, this means ratio of girls to boys.

Teacher’s Activities 3A – Group the pupils in 3 groups

Group 1 – Circles

Group 2 – Triangles

Group 3 – Squares

Groups Activities 3B – Identify the objects and colors on the chart.

*Group 1*

Circles – 4 Greens, 5 Blues, 7 Reds and 3 Yellows

*Group 2 *

Triangles – 4 Greens, 3 Blue, 3 Reds and 3 Yellows

*Group 3*

Squares – 6 Greens, 3 Blues, 4 Reds and 3 Yellows

Pupil’s Activities 4 – Express the ratio of greens to reds and yellows to blues

Group 1 – Circle1. Greens : Reds = 3 : 7

2. Yellows : Blues = 3 : 4

Group 2 – Triangles1. Greens : Reds = 4 : 3

2. Yellows : Blues = 3 : 3

Group 3 – Squares1. Greens : Reds = 4 : 3

2. Yellows : Blues = 3 : 3

Pupil’s Activities 5 – Class Exercises/Assignments

**Express the ratio of Diamond to Space and Heart to Space. **

Diamond – ♦♦♦♦♦♦♦♦

Heart – ♥♥♥

Space – ♠♠♠♠

Club – ♣♣♣♣♣

**LESSON 2 – EXPRESS RATIO IN SIMPLEST FORM**

Teacher’s/Pupil’s Activities 1 – Guide the Pupils Express Ration as Fractions

**Ratio can be expressed as fractions.**

Express the following ratio as fractions –

1. Diamond to Space= 8 : 4

= 8/4

2. Heart to Club= 3 : 5

= 3/5

3. Club to Heart= 5 : 3

=.5/3

4. Heart to Diamond= 3 : 8

= 3/8

Pupil’s Activities 2 – Ratio in Its Simplest form

Find the missing number –

1. 5 : 15 = 1 : 3

2. 8 : 6 = 4 : 3

3. 14 : 16 = 7 : 8

Teacher’s Activities 3 – Randomly ask the pupils how the questions are solved.

1. 5 : 15

= 5 : 15

= 1 x

~~:~~5~~x 3~~5= 1 : 3

2. 8 : 6

= 4 x

:~~2~~: 3~~2~~= 4 : 3

3. 14 : 16

= 7 x

:~~2~~x 8~~2~~= 7 : 8

Teacher’s remark – You are all right and correct. This working is called Ratio in Its Simplest form. You can also express the ratio as fractions, then simply.

That’s,

14 : 16

= 14/16

= (7 x~~2~~)/(8 x~~2~~)

= 7/8

Pupil’s Activities 4 – Class Exercises/Assignments

**Express the following as ratio of one another in their simplest form, **

1. 5 as a ratio of 15

2. 8 as a ratio of 64

3. 9 as a ratio of 27

**LESSON 3 – QUANTITATIVE REASONINGS ON RATIO**

As stated in their quantitative books and textbooks.

**LESSON 4 – PERCENTAGES**

Teacher’s/Pupil’s Activities 1 – Guide pupils to express ratio as percentageExpress the following ratio as percentage,

1. 4 : 5

2. 7 : 8

Step 1 – Express ratio as fractions.

1. 4 : 5

= 4/5

Step 2 – Multiple the fractions by 100.

= 4/5 x 100

Step 3 – Simply in its lowest form.

= (4 x 100)/5

= (4 x 20 x

)/~~5~~~~5~~= 4 x 20

= 80%

Follow the same procedure for the second question.

**Teacher’s remark – The above procedure is expressing ratio as percentage. Percent means per 100. 8****0% means 80 out 100. 80% is pronounced as 80 percent. 80% can also be written as 80/100 (fraction). **

This symbol (%) is used as percentage meaning 100.

Pupil’s Activities 2 – Class Exercises/Assignments

Express the following ratio as percentage,

1. 24 : 30

2. 6 : 18

3. 45 : 15

Relevant Lesson on Percentage, follow the link – Simple Problems on Percentages (Primary 5 and Primary 6)

**LESSON 5 – QUANTITATIVE REASONING ON PERCENTAGES**

As stated in their quantitative books or textbooks.

**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. Leads pupils to compare things using ratio.

Pupil’s Activities – Express things that are alike as ratio of another.

3. Asks pupils to solve quantitative problems on ratio.

Pupil’s Activities – solve quantitative problems on ratio.

4. Guides pupils to express ratio as percentage.

Pupil’s Activities – Follow the teacher’s instructions.

**CONCLUSION**

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

- Next Lesson –

**LESSON EVALUATION **

**Pupils to:**

1. recognise the idea of ratio.

2. simplify ratio in its lowest term.

3. express numbers as a percentage of another.

4. solve problems involving ratio.