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CBSE Class 4 Mathematics★ 4-5 marks through school tests, activities, notebook work, and competency questions in CBSE Class 4 Mathematics (Maths Mela)

The Cleanest Village

A CBSE Class 4 Mathematics (Maths Mela) chapter set in Mawlynnong, Asia's cleanest village. Through real-life situations — cleaning schedules, shopping, and managing waste — children practise addition, subtraction, estimation, number pairs, and money problems. These notes give core ideas, worked examples, an activity, common mistakes, a practice set with answers, and quick revision.

⏱ 16 min readEasy difficulty✓ Free · NCERT-aligned

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By the end of this chapter you'll be able to…

1Add and subtract larger numbers in word problems
2Use number pairs that make 10, 100, and 1000
3Solve money problems with totals and change
4Estimate to check answers
5Choose the correct operation from the words

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Why this chapter matters

The Cleanest Village, set in Mawlynnong, uses real-life situations to strengthen addition, subtraction, estimation, number pairs, and money problems. Children learn to choose operations and check answers in everyday contexts.

Before you start — revise these

A 5-minute refresher here will save you 30 minutes of confusion below.

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Addition and subtraction (Class 3)

Adding and subtracting with regrouping from Class 3.

The Cleanest Village — Class 4 Mathematics (CBSE)

From the current NCERT Maths Mela Grade 4 book, Chapter 7. In Mawlynnong — known as Asia's cleanest village — maths helps the community plan, shop, and keep clean.

1. Why this chapter matters

Maths is most useful when it helps in real life. In a clean village, people add and subtract to manage waste, money, and schedules. This chapter strengthens addition, subtraction, estimation, and money through friendly, real situations.

2. Core ideas

Idea 1 — Add and subtract to solve real problems

Join amounts → add; take away or find the difference → subtract.

Method 2 — Use number pairs to add quickly

Numbers that make 10, 100, or 1000 are handy: 60 + 40 = 100; 700 + 300 = 1000.

Skill 3 — Money: totals and change

Add prices to find a total; subtract to find the change. Estimate first to check.

3. Worked examples

Example 1: On Monday 240 kg of waste was collected, and 185 kg on Tuesday. How much in all?

240 + 185 = 425 kg.

Example 2: A bin holds 500 kg; 320 kg is in it. How much more will fit?

500 − 320 = 180 kg.

Example 3: A broom costs ₹45 and a basket ₹60. What is the total, and the change from ₹200?

Total = 45 + 60 = ₹105; change = 200 − 105 = ₹95.

4. Activity corner

Plan a "clean classroom" budget. List two cleaning items with prices, find the total, and the change from ₹100. Write:

The prices you added
The change you found
The maths idea (add for totals, subtract for change)

5. Common mistakes

Mistake: Adding when the problem says "how much more / left". Fix: "How much more" and "left" usually mean subtract.
Mistake: Not checking with an estimate. Fix: Estimate first; if the exact answer is far off, recheck.
Mistake: Forgetting the unit (kg or ₹). Fix: Always write the unit with the answer.

6. How to write better answers

Write the numbers given.
Decide add or subtract from the words.
Use number pairs to add quickly where possible.
Estimate, solve, and write the answer with its unit.

7. Practice set

Add: 340 + 275.
Subtract: 600 − 248.
Which two numbers make 100: 35 and ___?
A bag costs ₹85; you pay ₹100. What is the change?
360 kg of waste was collected in the morning and 290 kg in the evening. Find the total.
Estimate 480 + 210 to the nearest hundred.

8. Answer key

65 (35 + 65 = 100).
₹15 change.
360 + 290 = 650 kg.
About 500 + 200 = 700 (exact is 690).

9. Quick revision

Add to join amounts; subtract to take away or find the difference.
Number pairs make 10, 100, 1000 — they speed up addition.
Money: add for totals, subtract for change.
Estimate first to check your answer.
Always write the unit (kg, ₹) with the answer.

Key formulas & results

Everything you need to memorise, in one card. Screenshot this for revision.

Core idea

Add to join amounts; subtract to take away or find the difference.

Read the words to choose the operation.

Math move

Number pairs make 10, 100, or 1000 (60 + 40 = 100), which speeds up adding.

Look for pairs that complete a round number.

Exam habit

Money: add prices for totals, subtract for change; estimate to check.

Words like 'how much more' and 'left' mean subtract.

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Common mistakes & fixes

These are the exact errors that cost students marks in board exams. Read them once, save yourself the trouble.

WATCH OUT

✗ Adding when the problem says how much more or left

✓ How much more and left usually mean subtract.

WATCH OUT

✗ Not checking with an estimate

✓ Estimate first; if the exact answer is far off, recheck.

WATCH OUT

✗ Forgetting the unit (kg or rupees)

✓ Always write the unit with the answer.

NCERT exercises (with solutions)

Every NCERT exercise from this chapter — what it covers and how many questions to expect.

Read, observe, and discuss

Use the village and market situations in the textbook to decide add or subtract before writing answers.

Questions

Notebook practice

Word problems, number pairs, money totals and change, and estimation.

Questions

Project or activity

Plan a clean-classroom budget: find a total and the change from 100 rupees.

Questions

Practice problems

Try each one yourself before tapping "Show solution". Active recall > rereading.

Q1EASY· Add

Add: 340 + 275.

▶ Show solution

615.

Q2EASY· Subtract

Subtract: 600 - 248.

▶ Show solution

352.

Q3MEDIUM· Number pairs

Which number makes 100 with 35?

▶ Show solution

65, because 35 + 65 = 100.

Q4MEDIUM· Money

A bag costs 85 rupees; you pay 100 rupees. What is the change?

▶ Show solution

15 rupees change (100 - 85 = 15).

Q5MEDIUM· Word problem

360 kg of waste was collected in the morning and 290 kg in the evening. Find the total.

▶ Show solution

360 + 290 = 650 kg.

Q6HARD· Estimate

Estimate 480 + 210 to the nearest hundred and give the exact answer.

▶ Show solution

About 500 + 200 = 700; the exact answer is 690.

5-minute revision

The whole chapter, distilled. Read this the night before the exam.

•The Cleanest Village is Chapter 7 of the Class 4 Maths Mela textbook.
•Add to join amounts; subtract to take away or find the difference.
•Number pairs make 10, 100, 1000 - they speed up addition.
•Money: add for totals, subtract for change.
•Estimate first to check your answer.
•Always write the unit (kg, rupees) with the answer.

CBSE marks blueprint

Where the marks come from in this chapter — so you can plan your prep.

Typical chapter weightage: 4-5 marks in school tests, oral checks, notebooks, and activities

Question type	Marks each	Typical count	What it tests
Very Short	1	2-3	Direct sums or number pairs
Short Answer	2	1-2	Money or word problems
Activity / Project	3	0-1	Budget planning with totals and change

Prep strategy

Read word problems and underline the keyword
Use number pairs to add quickly
Practise money totals and change
Estimate before solving

Where this shows up in the real world

This chapter isn't just an exam topic — it lives in the world around you.

Managing money

Finding totals and change is used in shopping every day.

Planning and budgeting

Adding and subtracting helps plan schedules and budgets.

Keeping clean

Calculating waste and supplies supports a clean community.

Exam strategy

Battle-tested tips from teachers and toppers for this chapter.

Underline the keyword that signals add or subtract
Use number pairs to add quickly
Write money answers with the rupee sign
Check the answer with an estimate

Going beyond the textbook

For olympiad aspirants and curious learners — topics that build on this chapter.

Find three pairs of numbers that each make 1000.
Plan a 200-rupee budget for three items and show the change.

Where else this chapter is tested

CBSE board isn't the only one — other exams test this chapter too.

CBSE Class 4 School AssessmentHigh

Class 4 Foundation / Olympiad PracticeMedium

Notebook and Activity EvaluationHigh

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Questions students ask

The real ones — pulled from the Q&A community and tutor sessions.

Read the words. 'In all' and 'altogether' usually mean add; 'how much more', 'left', and 'change' usually mean subtract.

Number pairs are two numbers that add up to a round number like 10, 100, or 1000, such as 65 and 35 making 100. They make adding faster.

Practice more, ask doubts, find a tutor

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