# My School Trip

## Overview
In this chapter, students go on a journey with Daisy and Lou as they prepare for and experience a school trip to Mawlynnong, known as Asia’s cleanest village. Through this engaging context, learners explore practical applications of mathematics in everyday scenarios. The chapter develops skills in estimation, addition, subtraction, regrouping, and logical reasoning through shopping, puzzles, and word problems.

## Key Topics Covered

### 1. Preparing for the Trip
- **Trip Details**: Poster showing date, destination (Mawlynnong), cost, contact details, transport and attractions.
- **Math Link**: Location and population data introduced.

### 2. Shopping for the Trip
- **Items Purchased**: Fruits, vegetables, and other supplies.
- **Price List Exercise**: Children calculate the cost of various quantities from a list (e.g., 1 kg of radish = ₹23).
- **Math Focus**: Addition of different items to reach a total amount (e.g., what combinations total ₹163?).

### 3. Money Transactions and Balance
- **Balance Calculation**: Using cost and amount paid to find the balance returned.
- **Exercises**: Various problems where one value is missing (cost, paid, or balance).
- **Application**: Helps understand subtraction and reverse calculations.

### 4. Problem Solving: Banana Purchase
- **Scenario**: Buying 3 kg of bananas.
- **Exercise**: Students explore different combinations to pay for 3 kg based on banana cost (₹55/kg).

### 5. A Strange Puzzle
- **Situation**: Four children buy oranges priced at ₹21 each using different denominations.
- **Concept**: Subtraction of ₹42 from various notes (₹50, ₹100, ₹200, ₹500) to find balances.

### 6. Number Triangle Puzzle
- **Challenge**: Place numbers 1–6 so each side of a triangle adds up to a fixed sum (e.g., 9, 10).
- **Math Skill**: Logical reasoning and addition.

### 7. Total Number of Teachers and Children
- **Addition Exercises**:
- Teachers: 24 (from one school) + 28 (from another)
- Children: 438 + 476 = 914
- **Concepts**: Column addition, estimation, and regrouping of ones, tens, hundreds.

### 8. Estimating and Adding Money
- **Example**: Buying snacks (pusaw ₹38 + ₹16 = ₹54).
- **Activity**: Regrouping to solve 185 + 125 using column method.

### 9. Subtraction Situations
- **Examples**:
- Pusaw vs fruit plate buyers: 83 – 46 = 37
- Children waiting to see bridge: 438 – 215 = 223
- Remaining money from trip: 310 – 179 = ₹131
- **Concept**: Regrouping in subtraction using ones, tens, hundreds.

### 10. Festival and Farm Scenarios
- **Mangoes**: Compare mango yield over two years (264 vs 527).
- **Dolls**: Remaining dolls after selling (639 – 531).
- **Library**: Comparing pages of books read by different children.
- **Train Travel**: Find total passengers, alighted, and comparison across stations.

## 11. Subtraction and Addition Practice

- **Given Sums**:
- Add: 38 + 943, 465 + 305, etc.
- Subtract: 764 – 657, 518 – 209, etc.
- **Mental Math Strategy**: Estimate results and use strategies like skip counting or rounding.

## 12. Number Pairs and Grids
- **Grid Exercise**: Identify pairs of numbers with the largest and smallest sums and differences.
- **Critical Thinking**: Helps visualize arithmetic patterns in grids.

## 13. Missing Digits in Sums
- **Activity**: Fill in missing digits in addition sums to make them correct.
- **Skill**: Reverse calculation and logical number placement.

## 14. Final Exercises
- **Find Two Numbers**:
- Whose sum is 856.
- Whose difference is 563.
- **Create Word Problems**: Using these numbers.

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## New Terms and Definitions

| Term | Simple Definition |
|------------------|----------------------------------------------------------------|
| Estimation | Making a quick guess of the total or answer using rounding |
| Balance | The money returned when you pay more than the item cost |
| Regrouping | Rearranging numbers when adding or subtracting (e.g., 10 ones = 1 ten) |
| Puzzle | A problem or game that tests your thinking |
| Quantity | The amount or number of something |
| Column Method | Lining up numbers to add or subtract digit by digit |
| Denomination | The value of a note or coin (e.g., ₹50, ₹100) |
| Difference | The result of subtraction |
| Total | The result of addition |
| Number Pair | Two numbers placed side by side (horizontally or vertically) |

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## Practice Problems

### Easy (3 problems)
1. What is the total cost of 1 kg radish (₹23) and 1 kg yam (₹45)?
- ₹23 + ₹45 = ₹68

2. Subtract: 300 – 45
- ₹255

3. Add: 105 + 295
- ₹400

### Medium (2 problems)
4. Daisy paid ₹200 for something that cost ₹185. What is her balance?
- ₹200 – ₹185 = ₹15

5. Estimate and find the sum: 654 + 95
- Estimate: ≈750; Exact: 749

### Difficult (3 problems)
6. Lou had ₹310 and spent ₹179. How much is left?
- ₹310 – ₹179 = ₹131

7. 438 children plan to visit a place. 215 go first. How many are left?
- 438 – 215 = 223

8. Find the sum: 826 + 268
- ₹1,094

### Very Difficult (2 problems)
9. In a train, 894 people board at one station, 23 alight, 158 board at the next, 75 alight. How many people are now on the train?
- 894 – 23 + 158 – 75 = 954

10. Jaggu read: Swami and Friends (179), Akbar Birbal (96), 50 pages of Feluda. Total pages left in rest of books (Karadi Tales, Blue Umbrella, remaining Feluda)?
- Total = 30 + 90 + (128–50) = 30 + 90 + 78 = 198

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