Chapter 7 of the Class 4 Maths textbook Math Mela is The Cleanest Village. Set in Mawlynnong, a village in Meghalaya known as one of Asia’s cleanest villages, this chapter uses cleanliness and waste-collection data to teach addition and subtraction with regrouping, estimation, and money calculations.
Addition and Subtraction with Regrouping
Q: The village collected 3,486 kg of waste one month and 2,758 kg the next. What was the total waste collected over both months?
A: 3,486 + 2,758 = 6,244 kg. Adding column by column with regrouping (carrying over) at the ones, tens, and hundreds place gives the total.
Estimation
Q: Why might someone estimate the total waste collected instead of calculating the exact number?
A: Estimation gives a quick, rounded idea of the total (for example, rounding 3,486 to 3,500 and 2,758 to 2,750) when an exact figure isn’t needed immediately, making mental calculation faster.
Money and Balance Calculations
Q: If a shopkeeper is paid ₹500 for an item costing ₹342, how much balance (change) should be returned?
A: ₹500 − ₹342 = ₹158 balance.
Finding Missing Digits
Q: In the subtraction 5_7 − 249 = 308, what is the missing digit?
A: 5_7 − 249 = 308, so 5_7 = 308 + 249 = 557. The missing digit is 5.
Frequently Asked Questions
Which real village inspired this chapter?
Mawlynnong, a village in Meghalaya, India, widely known as one of the cleanest villages in Asia.
What does “regrouping” mean in addition and subtraction?
Carrying over (in addition) or borrowing (in subtraction) between place-value columns when a column’s digits add up to 10 or more, or when a column doesn’t have enough to subtract directly.
Class 4 Mathematics Chapter 7 – Notes and Extra Questions
Along with these NCERT Solutions, students can also use the Class 4 Mathematics Chapter 7 Extra Questions and Class 4 Mathematics Chapter 7 Revision Notes for quick revision and extra practice.
