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CBSE Class 4 · Mathematics

Data Handling

Official NCERT chapter from Math-Mela (book code demm1). ExamMaster notes are original teaching at CBSE Class 4 depth.

This lesson follows the official chapter “Data Handling” in Math-Mela. The words below are ExamMaster’s teaching, not a paste from the book. Use the NCERT chapter for the classroom sequence; use these notes to hold the idea without copying exercises or figures.

  • CBSE Class 4
  • Easy level
  • 8 concepts

1Favourite subject is one label at a time

One sort uses one label: maths, or games, or both-as-a-new-question. Mixing labels in one pile hides both counts.

A new question needs a new sort.

Figure. A favourite-subject poll is one label at a time. Each child is counted in exactly one box. The child drawn under Maths is not also drawn under Science.

How it works

  1. Pick one labelFavourite subject: maths.
  2. Make that pileOnly that vote.
  3. Write its countThen you may start a new label.

2Ask the class; one child, one mark

A poll is one mark per child per question. Two marks for one child doubles the pile.

The mark is the record, not the child.

Figure. Ask the class and make one mark per child. Eight children named Maths, so eight marks. A double tick for emphasis would silently add a ninth child.

How it works

  1. Ask one childOne vote.
  2. Make one markTally or pictograph unit.
  3. Do not add bonus marksLoud is not extra.

3Complete a table from the picture or the poll

If the pictograph shows 8 marks for games, the table cell must say 8. Complete means copy the honest count into the cell.

Inventing a 10 because the row looks empty is a lie.

Figure. Complete the table from the picture: count the boxes in each row. Maths 8, Science 6, Art 4, English 2. The number at the end of a row must match the boxes, not a guess.

How it works

  1. Count the picture marksOne label.
  2. Write that number in the tableSame label.
  3. Leave a blank only if you have not counted yetThen go count.

4The most liked subject is the biggest honest count

Most means the largest count after an honest one-to-one. A taller crayon bar that used a thicker line is a cheat.

Compare counts, not crayon size.

Figure. The most liked subject is the biggest honest count. Maths is 8, taller than Science 6, Art 4 and English 2. Tallest bar wins only because the scale is the same for every subject.

How it works

  1. Finish every row’s countSame mark size.
  2. Compare the numbersOr same-size marks.
  3. Name the largestThat label is the most.

5The least liked is the smallest honest count

Least is the smallest finished count. Zero is allowed if nobody chose that label.

Skipping a row does not make it least — it makes it missing.

Figure. The least liked subject is the smallest honest count. English is 2, shorter than Art 4, Science 6 and Maths 8. Shortest bar wins only on the same scale.

How it works

  1. Finish every rowIncluding zeros.
  2. Find the smallest numberThat is least.
  3. Do not ignore an empty honest row0 can be least.

6A pictograph needs a key

If one picture-mark means 2 children, 5 marks mean 10 children. Without a key, a mark is mute.

Do not assume one mark = 1 unless the key says so.

Figure. A pictograph needs one key for the whole chart. Here one box stands for 2 children, so 4 boxes are 8, 3 boxes are 6, 2 boxes are 4, 1 box is 2. Changing the key mid-chart would silently double a row.

How it works

  1. Read the key1 mark = ?
  2. Count the marksHow many pictures.
  3. Multiply by the keyThat is the count.

Pictograph with a key

Key: 1 book-picture = 2 children. Science shows 6 books. How many children chose science?

  • Key2 children per mark
  • Marks6
  • Count6 × 2 = 12

Pro tip. A pictograph without a key is mute. Multiply marks by the key.

7“How many more” subtracts two rows

How many more chose games than music is (games) − (music), after both rows are finished.

It is not a new subject pile.

Figure. “How many more” subtracts two honest rows. Maths 8 minus Science 6 is 2. The dashed rule sits at 6 so the extra height on Maths is the leftover 2.

How it works

  1. Finish both rowsTwo labels.
  2. Subtract the smaller from the largerIf the question is “more”.
  3. The difference is “how many more”Not a third subject.

8A table and a picture must agree

If the table says 12 and the pictograph (after the key) says 10, one record is wrong. Recount.

Do not “fix” it by a story.

Figure. A table and a picture must name the same counts. Maths 8, Science 6, Art 4, English 2 on the bars is the same list the pictograph rows already counted. If they disagree, one of them is wrong.

How it works

  1. Read the table cellA number.
  2. Compute the picture with the keySame label.
  3. Demand they matchOr recount both.
One picture-mark = 2 children. 5 marks mean
  1. 10 children
  2. 5 children
  3. 7 children

Marks times the key.

Notes

  • The official chapter title is “Data Handling”. Teach the school test for that title, not a contest shortcut.
  • If a step needs a later class, stop. The next official chapter will pick it up.

Formulas

  • Count = (pictograph marks) \times (key).
  • How many more = larger row - smaller row.

Reference tables

One child, one mark. The table and the pictograph (after the key) must agree.

Favourite-subject poll
SubjectMarks (key: 1 = 1 child)Count
Maths99
Games1414
Music66

Recap

Hold these pegs from the official chapter “Data Handling”. The wording is ExamMaster’s teaching, not a textbook recap.

Favourite subject is one label at a time
One sort uses one label: maths, or games, or both-as-a-new-question.
Ask the class; one child, one mark
A poll is one mark per child per question.
Complete a table from the picture or the poll
If the pictograph shows 8 marks for games, the table cell must say 8.
The most liked subject is the biggest honest count
Most means the largest count after an honest one-to-one.
The least liked is the smallest honest count
Least is the smallest finished count. Zero is allowed if nobody chose that label.
A pictograph needs a key
If one picture-mark means 2 children, 5 marks mean 10 children.

Practise Data Handling

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  • A 4-question practice set that ends the chapter
  • 1 quick check with worked explanations
  • Timed mocks scored with the real marking scheme
  • Readiness tracked per topic, kept on your device
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