THEME: RATIO AND PERCENTAGES
PREVIOUS LESSON – First Term Examination Links For Primary Schools
TOPIC: RATIO AND PERCENTAGES
1. Introduction to Ratio
2. Ratio in its Lowest
4. Word problems
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.
The teacher will teach the lesson with the aid of:
- Colours pen or marker – black, red, green and blue.
- Money – ₦100, ₦200, ₦500 and ₦1,000
- Number of pupils in the class – male and female
- Number of desk and table in the class.
Learners can multiply and divide numbers up to 100 and and 200.
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.
9 – Years Basic Education Curriculum
Lagos State Scheme of work
New Method Mathematics Book 6
All Relevant Materials
LESSON 1 – INTRODUCTION TO RATIO
STAGE 1 – Introduction (5 minutes)
- Displays chart of quantitative reasoning on division of number.
- Guides the pupils to solve the problems on the chart or board.
- The pupils read out the chart.
- Perform the basic problems on the chart/board.
Learning Points – Previous knowledge confirm.
STAGE 2 – Grouping (5 minutes)
- Groups the pupils into four groups – A, B, C, and D.
- Guide the pupils to choose a leader and secretary for its group.
- Gives each group an exercise book.
- Learning materials are given as stated.
- Belong to a group.
- Choose their leader and secretary.
- Receive writing material.
- Receive learning materials for their group.
Learning Points – Pupil’s group, leader and secretary confirm.
STAGE 3 – Introduction to Ratio
Teacher’s Activities – Guided instructions:
- Count the number of each color,
- Demonstrates how to write ratios to compare the quantities of the objects using colon – red : blue or black : red, etc.
- Write in figure red : blue, blue and red, black : blue, etc.
- Guides the pupils to know that as you compare objects or quantities, you are doing ratio.
- Count and record the number of each color.
- compare each color using colon – red : blue or black : red, etc.
- Write in figure – red : blue = 4 : 2, etc.
- Understand the concept of ratio.
Learning Points – the concept of ratio confirmed.
STAGE 4 – Conclusion
Teacher’s Activities – To conclude the lesson for the week, the teacher revises the entire lesson and links it to the following week’s lesson.
- Defines ratio as relationship between two or more objects.
- Assignment – Group A, count the number of chairs and desks in 5C. Group B, count the number of chairs and desks in 5A. Group C, count the number of chairs and desks in 5B. Group D. Group D, count the number chairs and desks in 4A.
- What is the ratio of chairs to desks or desks and tables.
- Write in figure ratio of chairs and desks.
- Next lesson will be simplifying a ratio in its lowest form.
- Define ratio as relationship between two or more objects.
- Write down the assignment and all instructions given.
Lesson Points – Conclusion and assignment.
LESSON DEVELOPMENT 2 – SIMPLIFYING A RATIO IN ITS LOWEST FORM
STAGE 1 – Previous Lesson (5 minutes)
- Define ratio.
- Write red and black as ratio.
- If red is 3 and black is 6, what is the red : black?
- Ratio is the relationship between two or more quantities. It is also used to compare two or more objects or quantities.
- Red : Black.
- Red : Black = 3 : 6.
Learning Points – previous knowledge confirm.
STAGE 2 – Assignment (5 minutes)
- Group A, B, C and D. What is the result of chairs and desks counted?
- What is the ratio chair to desk?
- Group A, chairs _____ and desks _____. Group B, chairs _____ and desks _____. Group C, chairs _____ and desks _____. Group D, chairs _____ and desks _____.
- Group A, chair : desk = _____ : _____. Group B, chair : desk = _____ : _____. Group C l, chair : desk = _____ : _____. Group C, chair : desk = _____ : _____.
Learning Points – Pupil’s groups assignment confirmed.
STAGE 3 – Relationship between Ratio and Fraction (10 minutes)
- Guides the pupils to write/express ratio as fraction and simplify.
- Leads them to express the fraction back to ratio.
- Lets the a presentative from each group to write its group result on the board.
- Chair : Desk = A : B is written as A/B. A/B = a/b.
- Chair : Desk = a/b is written back as a : b
Note – the teacher assumes number of chairs and desks to be A and B.
STAGE 4 – Conclusion/Evaluation/Assignment (20 minutes)
- Quick discussion of their experience finding and writing ratios and ask them to share a few responses to the topics they discussed in the writing exercise.
- Leads each group to count the number of males and females in its group.
- Collects the results of males and females and write them on the board.
- Asks each group to add up the results to get total number of males and females.
- Group A and B, find the ratio of males to females. While Group C and D, find the ratio of females to males.
- Compare the results of A, B, C and D for correction.
Ratio is the comparison of two or more quantities (objects). Fraction is part of a whole. The relationship between ratio and fraction is the expression of ratio as fraction. This does not mean the two are the same.
- Total number of males _____ and females _____.
- Group A and B, males : females = _____ : _____. Group C and D, females : males = _____ : _____.
- Presentation and Correction.
- Next lesson – percentage. What is percentage?
LESSON DEVELOPMENT 3 – PERCENTAGES
STAGE 1 – Previous Lessons (5 minutes)
- What is the total number of males and females in class?
- What is the ratio of females to males.
- What is ratio?
- Males ______ and Females ______.
- Males : Females = ______ : ______.
- Ratio is the comparison of two or more qualities.
Learning Points – Previous lessons confirmed.
STAGE 2 – Introduction to Percentage (10 minutes)
- Express the ratio of males : females as a fraction.
- Multiply by 100.
- Guides the pupils to understand the concept of percentage as 100%.
- Males : Female = A : B = A/B.
- A/B = a/b.
- a/b x 100 = _____
- Understand the concept of percentage as 100%.
Learning Points – The concept of percentage confirmed.
STAGE 4 – Word Problems on Ratio and Percentage (15 minutes)
Express each of the following ratio into percentage:
- Group A – 6 : 5
- Group B – 8 : 25
- Group – 10 : 50
- Group D – 4 : 5
- Group A – 6/5 = 6/5 × 100% = 600/5 = 120%
- Group B – 8/25 = 8/25 × 100% = 800/25 = 32%
- Group C – 10/50 = 10/50 = 1/5 × 100% = 100/5 = 20%
- Group D – 4/5 = 4/5 × 100% = 400/5 = 80%
Learning Points – Knowledge of word problems confirmed.
STAGE 4 – Conclusion/Assignment
- Ratio is the comparison of two or quantities. Ratio can be express as a fraction. Percentage means 100%.
- Find the percentage of 4 red makers in a pack if the pack contains 24 pieces.
- Recall the relationship between ratio, fraction and percentage.
- Take down the assignment.