Bar Graphs, Construction, Interpretation and Mode for Primary 4

Class: Primary 4
Term: Third Term
Week: 10
Age: 9 years
Duration: 45 minutes
Subject: General Mathematics
Curriculum Theme: Everyday Statistics
Focal competence: Prepare graph based on obtained data, reading/interpreting information from a graph
Key competencies/values: Information Literacy
Skills:

• Generating data
• Plotting graph with available data

Previous Lesson: Three-Dimensional Shapes, Open and Closed Shapes, Their Uses
Topic: Bar Graph
Subject Matter: Meaning of a bar graph, Constructing, reading and interpreting a simple bar graph, identifying the mode

Specific Objectives

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

Cognitive Domain

• explain the meaning of a bar graph;
• read a bar graph to extract information;
• identify the mode from a bar graph.

Affective Domain

• appreciate the use of bar graphs in presenting data clearly.

Psychomotor Domain

• draw a simple bar graph from given data.

Reference Materials

The following resources were used in planning this lesson:

• 2025 Revised 9 Years Basic Education Curriculum
• Relevant State Unified Scheme of Work
• Universal Primary Mathematics for Primary 4
• The HeadTeacher Scheme of work

Instructional Materials

The teacher will teach this lesson with the aid of:

• Bar graph charts
• Simple data (e.g., list of favourite fruits)
• Cardboards and markers
• Graph paper
• Rulers
• Pencils

Rationale for the Lesson

This lesson introduces pupils to bar graphs as a simple and effective way to represent and understand data. Understanding bar graphs helps pupils develop critical thinking skills by interpreting visual information, which is essential for making sense of statistics encountered in everyday life and future studies.

Prerequisite/Previous Knowledge

Pupils have prior knowledge of counting, comparing numbers, and collecting simple data.

Lesson Content/Board Summary

Bar Graph

Meaning of a Bar Graph

A bar graph is a chart that uses rectangular bars to show how many items are in different categories. The length or height of each bar represents the quantity or frequency of a particular item.

Parts of a Simple Bar Graph

1. Title: Tells what the graph is about.
2. Horizontal Axis (x-axis): Shows the categories or items being compared (e.g., types of fruits).
3. Vertical Axis (y-axis): Shows the frequency or number of items (e.g., number of pupils).
4. Scale: The numbering on the vertical axis that shows how much each unit represents (e.g., 1 unit = 1 pupil).
5. Bars: Rectangular shapes of equal width, separated by equal spaces, representing the data for each category.

Constructing a Simple Bar Graph

To construct a bar graph, follow these steps:

1. Collect or obtain the data you want to represent.
2. Draw a horizontal axis and a vertical axis.
3. Label the horizontal axis with the categories (e.g., types of fruits).
4. Label the vertical axis with the frequency (e.g., number of pupils).
5. Choose an appropriate scale for the vertical axis (e.g., each line represents 1, 2, or 5 units).
6. Draw bars of equal width for each category. The height of each bar should correspond to its frequency on the vertical axis.
7. Ensure there is equal space between the bars.
8. Give your bar graph a clear title.

Example: Favourite Fruits of Pupils in a Class

A survey was conducted among Primary 4 pupils to find their favourite fruits. The results are:

1. Apple: 5 pupils
2. Banana: 7 pupils
3. Orange: 3 pupils
4. Mango: 6 pupils

To draw this bar graph:

1. Draw axes.
2. Label the horizontal axis “Fruits” and the vertical axis “Number of Pupils”.
3. Choose a scale where 1 unit on the vertical axis represents 1 pupil.
4. Draw bars for Apple (height 5), Banana (height 7), Orange (height 3), and Mango (height 6).
5. Give the graph a title: “Favourite Fruits of Primary 4 Pupils”.

Reading and Interpreting a Simple Bar Graph

To read and interpret a bar graph, look at the height of each bar and match it to the corresponding value on the vertical axis. This tells you the frequency for each category. You can then answer questions like:

1. Which category has the highest frequency?
2. Which category has the lowest frequency?
3. What is the frequency of a specific category?
4. How many items are there in total?

Identifying the Mode in a Bar Graph

The mode in a set of data is the item or category that appears most frequently. In a bar graph, the mode is represented by the tallest bar. It shows the category with the highest number of occurrences.

From the “Favourite Fruits” example above, the tallest bar is “Banana” with 7 pupils. Therefore, “Banana” is the mode.

Teaching Methods/Instructional Techniques

Discussion, Demonstration, Guided Practice, Question and Answer, Explanation, Practical Activity

Instructional Procedures

Step 1: Introduction

Time: 5 minutes

Teaching Skill: Engaging/Recalling

Teacher’s Activity: The teacher greets the pupils and asks them how they can show information like “how many pupils like apples” or “how many pupils like oranges” in a picture form. The teacher then introduces the topic: Bar Graphs.

Pupils’ Activity: Pupils respond to questions and listen attentively.

Learning Point: Introduction to bar graphs

Step 2: Meaning of a Bar Graph

Time: 7 minutes

Teaching Skill: Explaining/Defining

Teacher’s Activity: The teacher explains what a bar graph is using a pre-drawn chart or example. The teacher highlights that it uses bars to show quantities and makes comparisons easy.

Pupils’ Activity: Pupils listen and observe the example bar graph, asking questions for clarification.

Learning Point: Bar graph definition

Step 3: Constructing a Bar Graph (Data Collection)

Time: 8 minutes

Teaching Skill: Guiding/Facilitating

Teacher’s Activity: The teacher guides pupils to collect a small class dataset, e.g., “favourite colours” or “favourite fruits”, by asking pupils to raise hands for their choices and recording the numbers on the board.

Pupils’ Activity: Pupils participate in data collection by stating their preferences and helping to count the frequencies.

Learning Point: Data collection process

Step 4: Constructing a Bar Graph (Drawing)

Time: 8 minutes

Teaching Skill: Demonstrating/Supervising

Teacher’s Activity: The teacher demonstrates on the board how to draw the axes, label them, choose a scale, and draw the bars for the collected data. Pupils are guided to draw their own bar graphs on graph paper.

Pupils’ Activity: Pupils draw the bar graph in their notebooks or on graph paper, following the teacher’s demonstration and guidance.

Learning Point: Bar graph drawing

Step 5: Reading a Bar Graph

Time: 5 minutes

Teaching Skill: Questioning/Interpreting

Teacher’s Activity: Using the bar graph they just drew (or a pre-prepared one), the teacher asks pupils questions like “How many pupils like [specific fruit]?” or “Which fruit is liked by most pupils?”.

Pupils’ Activity: Pupils read the bar graph and answer the teacher’s questions, pointing to the relevant bars.

Learning Point: Information interpretation

Step 6: Identifying the Mode

Time: 4 minutes

Teaching Skill: Explaining/Identifying

Teacher’s Activity: The teacher explains that the mode is the item that appears most often. The teacher then guides pupils to identify the tallest bar on their graph and state what it represents, which is the mode.

Pupils’ Activity: Pupils identify the tallest bar and state the mode of the data from their bar graph.

Learning Point: Mode identification

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 a bar graph?
2. How do you know which item is the mode on a bar graph?
3. Draw a simple bar graph for the following data:
   • Red: 4
   • Blue: 6
   • Green: 2
4. From your graph, how many items are “Blue”?

Pupils’ Activity: Pupils answer orally and in writing.

Learning Point: Lesson understanding check

Step 8: Note-Taking

Time: 4 minutes

Teaching Skill: Guided Writing

Teacher’s Activity: The teacher guides pupils to copy the essential Board Summary notes on the meaning, construction, reading, and mode of a bar graph into their notebooks.

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

Learning Point: Notes copying

Step 9: Conclusion

Time: 2 minutes

Teaching Skill: Summarizing/Reinforcing

Teacher’s Activity: The teacher briefly summarizes the key points of the lesson, emphasizing the importance of bar graphs for presenting and understanding data. The teacher encourages pupils to look for bar graphs in newspapers or books.

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

Learning Point: Lesson summary

Continuous Assessment/Further Study

Type: Homework

Instruction: Collect data from 10 family members or neighbours about their favourite types of food (e.g., Rice, Yam, Beans, Garri). Then, use the data to:

1. Draw a bar graph on a sheet of graph paper.
2. Label all parts of your bar graph.
3. Identify the mode (most favourite food) from your graph.

Lesson Keywords

• Bar Graph – A chart using bars to show data.
• Axis – A reference line on a graph (horizontal or vertical).
• Frequency – The number of times an item appears.
• Scale – The values represented by units on the axis.
• Mode – The item that appears most frequently in a dataset.

Differentiation

For weaker learners, provide pre-drawn axes and a simpler, smaller dataset with clear instructions for drawing bars. For faster learners, challenge them to create two different questions that can be answered by reading their bar graph, or ask them to represent the same data using a different scale.

Suggested Lesson Videos

Search on YouTube for: bar graphs for primary 4 mathematics

Teacher Guide for Using This Lesson Plan

Before the lesson, ensure you have a simple, relevant dataset prepared for the class activity, such as favourite colours, fruits, or subjects. Have graph paper, rulers, and pencils readily available for each pupil. Begin by engaging pupils with a simple question to connect to their prior knowledge of data. Clearly demonstrate how to draw and label the axes, choose an appropriate scale, and construct the bars, emphasizing equal width and spacing. Guide pupils step-by-step through the construction process, providing individual support as needed. When reading and interpreting, ask varied questions to ensure comprehensive understanding. The Board Summary should be copied by pupils after the main teaching and practice activities, typically in Step 8. Pay attention to common errors like inconsistent bar spacing or incorrect scaling. Encourage faster learners to create their own data and graphs, while providing simpler, pre-structured tasks for those who need more support. Ensure pupils understand that the tallest bar always represents the mode.