Demand and Supply, Schedules and Laws for SS 1

Class: SS 1
Term: Third Term
Week: 4
Age: 15 years
Duration: 60 minutes
Subject: Economics
Curriculum Theme: Business Organization
Focal competence: Using the dynamics of the forces of demand and supply to analyze real life market situation
Key competencies/values: Collaboration
Skills:

• Determining the dynamics of market prices in relation to demand and supply

Previous Lesson: Scale of production
Topic: Theory Of Demand And Supply
Subject Matter: Meaning of demand and supply, Demand and supply schedules, Law of demand and supply

Specific Objectives

By the end of the lesson, pupils/students should be able to:

Cognitive Domain

• Define demand and supply.
• Interpret demand and supply schedules.

Psychomotor Domain

• Construct demand and supply schedules.
• Draw demand and supply curves, showing the relationship between price and quantity.

Reference Materials

The following resources were used in planning this lesson:

• 2025 New Revised Senior Secondary Education Curriculum (SSEC)
• Relevant State Unified Scheme of Work
• A suitable Economics textbook for Senior Secondary 1
• The HeadTeacher Scheme of work For The New Revised Senior Secondary Education Curriculum (SSEC)

Instructional Materials

The teacher will teach this lesson with the aid of:

• Textbooks
• Graph papers and rulers
• Posters and visuals illustrating demand and supply concepts
• Newspaper clippings on real market trends (e.g. petrol prices, food inflation)
• Whiteboard/Blackboard and markers/chalk

Rationale for the Lesson

Understanding demand and supply is fundamental to comprehending how markets operate and prices are determined. This lesson provides students with the analytical tools to understand consumer behaviour and producer decisions, which are essential for making informed economic choices in their daily lives and for future studies in economics.

Prerequisite/Previous Knowledge

Students should have a basic understanding of economic concepts such as scarcity, choice, and opportunity cost.

Lesson Content/Board Summary

Theory Of Demand And Supply

Meaning of Demand

Demand refers to the quantity of a commodity that consumers are willing and able to purchase at various prices over a given period of time. It is not just about wanting a product, but also having the financial capacity to buy it.

1. Willingness: The desire to own a good or service.
2. Ability: The financial means to pay for the good or service.
3. Price: The cost at which the good or service is offered.
4. Time: Demand is always considered over a specific period (e.g., daily, weekly, monthly).

Demand Schedule

A demand schedule is a table that shows the different quantities of a commodity that consumers are willing and able to buy at various prices over a specific period. It illustrates the inverse relationship between price and quantity demanded.

Example: Demand Schedule for Rice in a Nigerian Market

1. Price per Bag (₦) | Quantity Demanded (Bags)
2. 50,000 | 100
3. 45,000 | 150
4. 40,000 | 200
5. 35,000 | 250
6. 30,000 | 300

Law of Demand

The Law of Demand states that, all other factors remaining constant (ceteris paribus), the higher the price of a commodity, the lower the quantity demanded, and the lower the price, the higher the quantity demanded. This inverse relationship means that as price increases, consumers buy less, and as price decreases, they buy more.

For example, if the price of petrol increases significantly in Nigeria, consumers will likely reduce their consumption by driving less or seeking alternative transport. Conversely, if the price of local garri falls, more households will be willing and able to purchase it.

Meaning of Supply

Supply refers to the quantity of a commodity that producers are willing and able to offer for sale at various prices over a given period of time. It reflects the producers’ desire and capacity to bring goods to the market.

1. Willingness: The desire of producers to sell a good or service.
2. Ability: The capacity of producers to produce and deliver the good or service to the market.
3. Price: The cost at which the good or service can be sold.
4. Time: Supply is also considered over a specific period.

Supply Schedule

A supply schedule is a table that shows the different quantities of a commodity that producers are willing and able to offer for sale at various prices over a specific period. It illustrates the direct relationship between price and quantity supplied.

Example: Supply Schedule for Rice in a Nigerian Market

1. Price per Bag (₦) | Quantity Supplied (Bags)
2. 50,000 | 300
3. 45,000 | 250
4. 40,000 | 200
5. 35,000 | 150
6. 30,000 | 100

Law of Supply

The Law of Supply states that, all other factors remaining constant (ceteris paribus), the higher the price of a commodity, the higher the quantity supplied, and the lower the price, the lower the quantity supplied. This direct relationship means that as price increases, producers are incentivized to produce and sell more, and as price decreases, they produce and sell less.

For instance, if the price of tomatoes increases sharply due to scarcity, farmers will be encouraged to plant more tomatoes and bring more of their existing stock to the market. Conversely, if the price of a cash crop like cocoa falls, farmers might reduce their output or switch to other crops.

Teaching Methods/Instructional Techniques

Discussion, Explanation, Question and Answer, Demonstration, Guided Practice, Group Work

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Activating Prior Knowledge

Teacher’s Activity: The teacher greets the students and asks them about their experiences buying goods in the market. “What happens to the amount of a product people buy when its price goes up or down?” The teacher then introduces the topic: Theory of Demand and Supply.

Pupils’ Activity: Pupils respond to the questions and share their experiences, linking them to price changes.

Learning Point: Market price experiences

Step 2: Meaning of Demand

Time: 10 minutes

Teaching Skill: Explanation/Definition

Teacher’s Activity: The teacher explains the meaning of demand, emphasizing the two key components: willingness and ability to buy. The teacher uses a simple classroom game (e.g., offering candy at different prices) to illustrate how willingness to buy changes with price.

Pupils’ Activity: Pupils listen, ask questions, and participate in the classroom game, observing how their demand for candy changes with price.

Learning Point: Definition of demand

Step 3: Demand Schedule and Law

Time: 10 minutes

Teaching Skill: Demonstration/Discussion

Teacher’s Activity: The teacher presents a simple demand schedule (e.g., for pens or a common food item like bread) on the board and explains how to interpret it. The teacher then explains the Law of Demand, using the schedule and real-life Nigerian examples (e.g., price of yam, fuel). The teacher guides students to provide a list of prices and quantities for a product and draw a simple demand curve on graph paper.

Pupils’ Activity: Pupils observe the demand schedule, discuss the examples, and practice drawing a demand curve on graph paper with teacher guidance.

Learning Point: Demand schedule and law

Step 4: Meaning of Supply

Time: 10 minutes

Teaching Skill: Explanation/Definition

Teacher’s Activity: The teacher explains the meaning of supply, focusing on the producers’ willingness and ability to sell. The teacher uses a similar classroom game or scenario (e.g., how many pens a student would be willing to “sell” at different prices) to illustrate the concept from a seller’s perspective.

Pupils’ Activity: Pupils listen, ask questions, and participate in the scenario, understanding supply from a producer’s viewpoint.

Learning Point: Definition of supply

Step 5: Supply Schedule and Law

Time: 10 minutes

Teaching Skill: Demonstration/Discussion

Teacher’s Activity: The teacher presents a simple supply schedule (e.g., for pens or a common agricultural product) on the board and explains its interpretation. The teacher then explains the Law of Supply, using the schedule and real-life Nigerian examples (e.g., supply of maize, cement). The teacher guides students to provide a list of prices and quantities for a product and draw a simple supply curve on graph paper.

Pupils’ Activity: Pupils observe the supply schedule, discuss the examples, and practice drawing a supply curve on graph paper with teacher guidance.

Learning Point: Supply schedule and law

Step 6: Relationship between Price and Quantity

Time: 5 minutes

Teaching Skill: Synthesis/Application

Teacher’s Activity: The teacher reviews the inverse relationship for demand and the direct relationship for supply, reinforcing how price acts as an incentive for both consumers and producers. The teacher uses newspaper clippings on market trends (e.g., petrol prices, food inflation) to show real-world applications.

Pupils’ Activity: Pupils engage in a brief discussion, relating the concepts to current events and interpreting market trends.

Learning Point: Price-quantity relationships

Step 7: Evaluation/Review

Time: 5 minutes

Teaching Skill: Questioning/Assessment

Teacher’s Activity: The teacher evaluates the learning by asking the following questions:

1. What is demand?
2. State the Law of Supply.
3. Construct a simple demand schedule for a product of your choice.
4. How does a demand curve differ from a supply curve?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Demand and supply understanding

Step 8: Note-Taking

Time: 10 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils/students to copy the essential Board Summary notes on the meaning of demand and supply, their schedules, and laws into their notebooks.

Pupils’ Activity: Pupils/students copy the notes carefully into their notebooks.

Learning Point: Recording lesson content

Step 9: Conclusion

Time: 5 minutes

Teaching Skill: Consolidation

Teacher’s Activity: The teacher briefly summarizes the main points of the lesson, reiterating that demand and supply are fundamental forces determining prices and quantities in a market economy. The teacher encourages students to observe these forces in their daily lives.

Pupils’ Activity: Pupils listen attentively and ask any final clarifying questions.

Learning Point: Core concepts reinforced

Continuous Assessment/Further Study

Type: Homework/Practice Exercise

Instruction: Answer the following questions in your notebook.

1. Define demand and supply in your own words.
2. Create a hypothetical supply schedule for a product like ‘pure water’ in your community, showing at least five different prices and corresponding quantities supplied.
3. Using the demand schedule you created in class (or a new one), draw a demand curve on a graph sheet. Label your axes clearly.
4. Explain the Law of Demand with a practical example from Nigeria.

Lesson Keywords

• Demand – The quantity of a good consumers are willing and able to buy at various prices.
• Supply – The quantity of a good producers are willing and able to sell at various prices.
• Demand Schedule – A table showing quantities demanded at different prices.
• Supply Schedule – A table showing quantities supplied at different prices.
• Law of Demand – Inverse relationship between price and quantity demanded.
• Law of Supply – Direct relationship between price and quantity supplied.
• Ceteris Paribus – All other factors remaining constant.

Differentiation

Support: For students struggling with drawing curves, provide pre-drawn axes or partially completed schedules. Pair them with stronger students for guided practice. Use simpler, more relatable examples.

Extension: Challenge advanced students to research factors that can shift demand or supply curves (e.g., income, technology) and discuss how these factors would affect the schedules and curves.

Suggested Lesson Videos

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