NCERT Solutions for Class 4th Maths Chapter 7 The Cleanest Village
Updated on 2026-09-19
About this chapter
We work with money, people and pages using a number line, play money or place-value tokens. In column addition and subtraction we write H, T and O one below the other, and always start from the ones. When a column fills up to ten we regroup: 10 ones make 1 ten, 10 tens make 1 hundred, 10 hundreds make 1 thousand. When there are not enough ones to take away, we regroup 1 ten as 10 ones; when there are not enough tens, we regroup 1 hundred as 10 tens. Balance = Paid − Cost, so Cost + Balance always gives back the money paid. We estimate first by rounding, then check that the real answer is close to the estimate. Some sums are quicker without columns: 811 + 99 is 811 + 100 − 1, and 410 − 12 is 410 − 10 − 2.
- Daisy and Lou Go Shopping
- Help Udaya Didi find the missing numbers
- Four children and the orange seller
- The triangle puzzle
- Add Up
- Kalakshitij, column sums and Preeti’s school
- Subtract It
- Ram Chacha’s mangoes and Ranganna’s dolls
- Question 5
- Question 1
Quick revision
| Idea | What it means | Example from the chapter | Answer |
|---|---|---|---|
| Regrouping in addition | 10 ones become 1 ten | 24 + 28 → 4 T + 12 O | 52 |
| Regrouping in addition | 10 tens become 1 hundred | 438 + 476 → 8 H + 10 T + 14 O | 914 |
| Regrouping twice | ones and tens both fill up | 185 + 125 → 2 H + 10 T + 10 O | 310 |
| Regrouping in subtraction | 1 ten becomes 10 ones | 83 − 46 → 7 T and 13 O | 37 |
| Regrouping in subtraction | 1 hundred becomes 10 tens | 310 − 179 | 131 |
| No regrouping needed | every column is big enough | 438 − 215 | 223 |
| Balance | Paid − Cost | Cost ₹185, paid ₹200 | ₹15 |
| Estimate | round, then add or subtract | 438 + 476 ≈ 400 + 500 | about 900 |
| Quick way to add | add a round number, take the extra off | 811 + 99 = 811 + 100 − 1 | 910 |
| Quick way to subtract | take away in easy steps | 410 − 12 = 410 − 10 − 2 | 398 |
| Doubling | double the quantity, double the cost | 1 kg onion + 1 kg potato = ₹69 | 2 kg each = ₹138 |
Exercises
- Daisy and Lou Go Shopping — In-text Questions Page 97
- Help Udaya Didi find the missing numbers — In-text Questions Page 98
- Four children and the orange seller — A Strange Puzzle! Page 99
- The triangle puzzle — Let Us Play Page 100
- Add Up — In-text Questions Page 101
- Add Up — In-text Questions Page 102
- Add Up — In-text Questions Page 103
- Add Up — In-text Questions Page 104
- Kalakshitij, column sums and Preeti’s school — Let Us Do Page 105
- Subtract It — In-text Questions Page 106
- Subtract It — In-text Questions Page 107
- Ram Chacha’s mangoes and Ranganna’s dolls — Let Us Solve Page 108
- Question 5 — Let Us Solve Page 109
- Question 1 — Let Us Solve Page 109 to 110
- Question 2 — Let Us Solve Page 110 to 111
- Column frames, quick ways and notebook practice — Let Us Solve Page 111
- Question e — Let Us Solve Page 112
- The grid of numbers — Number Pair Hunt Page 112 to 113
- Fill the missing digits — The Missing Digits Page 113
- Practice: add and subtract — Let Us Do Page 114