📚 Module 4: Powers, Data, and Probability

📈 Lesson 2: Collecting and Handling Data (Statistics) – Charts, Graphs, and Interpretation

📝 Introduction

Have you ever taken part in a class vote or counted how many students bring rice for lunch? That’s data collection!
In this lesson, you’ll learn how to collect, organize, display, and interpret data using tables, charts, and graphs. These are tools that help us see patterns and make decisions. Whether it’s for school elections, sports scores, or survey results — data handling is a key life skill!

🧠 Key Concepts

🔢 1. What is Data?

Data refers to pieces of information, facts, or numbers collected to study or analyze something.

• Raw Data: Unorganized facts. E.g., shoe sizes of students: 38, 40, 39, 38, 40
• Organized Data: Data arranged in a clear format — often in a table or chart.

📋 2. Methods of Collecting Data

We can collect data using:

• Surveys (questionnaires or interviews)
• Observation (watching and recording)
• Experiments (like recording rainfall daily)

📊 3. Frequency Tables

This is a table that shows how often each item or category occurs.

Example: Shoe sizes of 10 students: 38, 39, 38, 40, 39, 38, 38, 40, 39, 38

📈 4. Types of Graphs

📉 a. Bar Charts

Uses rectangular bars to represent quantities. Heights of bars match the frequency.

Bar chart showing shoe sizes (x-axis) and number of students (y-axis)

📘 b. Pictograms

Uses pictures or symbols to represent numbers. A key shows how much each symbol is worth.

Example: Number of books read by students:

• A book icon 📘 = books
• Mary: 📘📘📘 (3 books)
• Kojo: 📘📘 (2 books)
• Amma: 📘📘📘📘 (4 books)

🥧 c. Pie Charts

A circle divided into sectors. Each sector shows the portion of a category.

Example: Favourite fruits among 30 pupils: Mango (12), Orange (9), Banana (6), Apple (3)

Each fruit’s angle =

• Mango:
• Orange:
• Banana:
• Apple:

📈 d. Line Graphs

Used to show changes over time. Points are plotted and connected with straight lines.

Line graph showing rainfall over 7 days (x-axis = days, y-axis = mm of rain)

🔍 Sample Problem Walkthroughs

✅ Example 1: Drawing a Frequency Table

Question: The marks scored by 8 students in a quiz were: 4, 6, 4, 5, 6, 7, 6, 5

Solution:

✅ Example 2: Interpreting a Bar Chart

Question: A bar chart shows students who play these sports: Football (12), Volleyball (8), Basketball (5).
Which sport is least played?

Answer: Basketball (5 students).

✅ Example 3: Drawing a Pie Chart

Question: Out of 40 students: 20 prefer rice, 10 like yam, 10 like kenkey.
Find the angles for each sector of the pie chart.

• Rice:
• Yam:
• Kenkey:

📊 Practice Exercises

Part A: Frequency Table

The number of goals scored by a team in 7 matches: 2, 3, 1, 2, 3, 0, 1

Draw a frequency table to organize this data.

Part B: Pictogram Interpretation

Each 🏀 = 5 players

• Class A: 🏀🏀🏀
• Class B: 🏀🏀
• Class C: 🏀🏀🏀🏀

How many players in Class C?
Which class had the fewest players?

Part C: Pie Chart Angles

In a survey of 60 students:

• 24 use WhatsApp
• 18 use TikTok
• 12 use Instagram
• 6 use others

Find the angle for each sector.

📝 Answers and Explanations

Part A:

Part B:

• Class C: 4 × 5 = 20 players
• Class B had the fewest (2 × 5 = 10 players)

Part C:

• WhatsApp:
• TikTok:
• Instagram:
• Others:

✅ Recap

In this lesson, we explored how to collect, organize, and present data.
You learned about frequency tables, bar charts, pictograms, pie charts, and line graphs.
These tools help us understand data better and make smart decisions.

💭 Reflection Prompt

Think of a question you could ask your classmates, like “What’s your favorite school subject?”
How would you collect and display the answers using a table and a chart?
Sketch a rough version on paper to practice.