Data Handling — Class 4 Mathematics (CBSE)
From the current NCERT Maths Mela Grade 4 book, Chapter 14. Information is everywhere — let us collect it, organise it, and read it.
1. Why this chapter matters
We are surrounded by data — favourite fruits, marks, rainfall. Learning to collect, organise, and show data in tables, pictographs, and bar graphs helps us compare and answer questions quickly and clearly.
2. Core ideas
Idea 1 — Data is information we collect
We gather information, then organise it in a table using tallies or numbers.
Method 2 — A pictograph uses a symbol and a key
In a pictograph, one symbol stands for a number (the key). If 1 ⬤ = 5, then 4 ⬤ = 20.
Skill 3 — A bar graph uses bars
In a bar graph, the length (or height) of a bar shows the number. Longer bar = more.
3. Worked examples
Example 1: In a fruit table, apples have 8 and bananas 5. Which is more, and by how much?
Apples are more, by 8 − 5 = 3.
Example 2: A pictograph uses 1 ⬤ = 5 books. A shelf shows 4 ⬤. How many books?
4 × 5 = 20 books.
Example 3: In a bar graph, cricket has the tallest bar. What does that mean?
Cricket is the most popular (it has the highest number).
4. Activity corner
Ask 10 friends their favourite colour. Make a tally table, then draw a small bar graph. Write:
- Your table with tallies
- The most and least favourite colour
- The maths idea (organising and reading data)
5. Common mistakes
- Mistake: Reading a pictograph without using the key. Fix: Multiply the number of symbols by the key value.
- Mistake: Making bars of different widths. Fix: Keep bars the same width; only their length should change.
- Mistake: Miscounting tallies. Fix: Group tallies in fives (IIII crossed) to count easily.
6. How to write better answers
- Read the table, pictograph key, or bar graph carefully.
- For a pictograph, multiply symbols by the key.
- To compare, find the most, least, total, or difference.
- Write the answer with what it stands for.
7. Practice set
- What do we call information that we collect?
- In a pictograph, what does the key tell us?
- If 1 ⬤ = 10 and a row has 3 ⬤, how many is that?
- In a bar graph, what does the tallest bar show?
- In a table, football has 12 and hockey 7. How many more like football?
- How do we count tallies easily?
8. Answer key
- Data.
- How many each symbol stands for.
- 3 × 10 = 30.
- The largest number (the most popular item).
- 12 − 7 = 5 more.
- Group them in fives.
9. Quick revision
- Data is information we collect and organise.
- Use tables with tallies, pictographs, and bar graphs.
- A pictograph's key tells how many each symbol stands for.
- In a bar graph, a longer bar means a bigger number.
- Read graphs to find most, least, total, and difference.
