# Thousands Around Us

## Overview

In this chapter, students explore numbers up to and beyond one thousand using real-life contexts, such as community events, population data, and donations. The chapter strengthens their understanding of place value (ones, tens, hundreds, and thousands), number formation, comparison, and estimation. Tools like Dienes blocks, tokens, number lines, and arrow cards are used to visualize and manipulate numbers.

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## Key Topics Covered

### 1. Real-Life Numbers and Estimation
- Jaspreet and Gulnaz organize a community lunch (langar) for 1000 people.
- Use of donations and volunteer count to introduce 2-digit and 3-digit numbers in real-life.
- Practice writing numbers like "4 ones + 7 tens" and solving expressions such as "100 – 7".
- Time slots and headcounts help to use HTO (Hundreds-Tens-Ones) blocks for visual representation.

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### 2. Making and Marking Numbers
- Make 3-digit numbers using selected digits (e.g. using 3 and 7).
- Create 3-digit numbers less than 550 using digits 3, 5, 0, 8.
- Place the numbers on a number line between 200 and 600 to understand relative magnitude.
- Practice comparing and ordering numbers.

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### 3. Number Sequences and Patterns
- Fill-in-the-blank activities to identify consecutive numbers or compare numbers like 367 and 567.
- Visual grids for counting and understanding numbers up to 1000.

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### 4. Writing and Reading Numbers in Indian System
- Learn how to write numbers beyond 1000 using ten symbols (0–9).
- Explore large numbers like 5000 (years of history) or 7500 (km of coastline).
- Example: 1000 = 1 Thousand, 1001 = 1 Thousand + 1

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### 5. Dienes Blocks and Place Value
- Use Dienes blocks to visualize 1 (ones), 10 (tens), 100 (hundreds), and 1000 (thousands).
- Break numbers into parts, e.g., 900 + 100 = 1000 or 850 + 150 = 1000.
- Practice regrouping:
- 30 + 4 = 34 → 3 Tens + 4 Ones
- 200 + 50 = 250 → 2 Hundreds + 5 Tens

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### 6. Grouping and Regrouping Numbers
- Circle and count sets of 10s and 100s from a group of blocks or pictures.
- Identify and express numbers like:
- 14 Ones = 1 Ten + 4 Ones
- 1 Hundred + 0 Tens + 6 Ones = 106

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### 7. Expanded Form and Token Representation
- Write numbers in expanded form using place value:
- 1001 = 1000 + 1
- 1038 = 1000 + 30 + 8
- Use tokens or arrow cards to represent 4-digit numbers like 3452.

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### 8. Number Comparison and Number Line
- Compare numbers using <, >, and = based on place value.
- Example: 3102 > 3012 because hundreds place is greater.
- Plotting numbers like 2025, 2080, 2430 on a number line.

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### 9. Increasing and Decreasing Numbers
- Use place value sliders to increase/decrease numbers:
- 1895 + 1 = 1896
- 3369 – 2 = 3367

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### 10. Application through Fun and Challenges
- Find numbers between a range (e.g. how many between 7000–8000).
- Create 4-digit numbers using a given set of digits (e.g., 2, 3, 4, 7).
- Sort data like cricket scores or mountain heights by value.
- Practice comparisons in real-world contexts like number of plates used per month.

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## New Terms and Simple Definitions

| Term | Simple Definition |
|-----------------|------------------|
| Thousand | 1000 units |
| Place Value | Value of a digit depending on its position (ones, tens, hundreds, etc.) |
| Dienes Blocks | Learning tools to show 1s, 10s, 100s, and 1000s using blocks |
| Tokens | Items used to represent numbers (like blocks or pictures) |
| Expanded Form | A number written by showing the value of each digit (e.g. 1024 = 1000 + 20 + 4) |
| Arrow Cards | Cards used to represent digits in a number to show their place value |
| Regrouping | Rearranging groups of 1s, 10s, 100s to simplify or understand numbers |
| Indian Number System | A way of writing numbers using commas after hundred, thousand, etc. (e.g. 1,23,456) |

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## Practice Questions with Answers and Explanations

### Easy (3)
1. **What is 4 Hundreds + 5 Tens + 2 Ones?**
**Answer**: 452
**Explanation**: 400 + 50 + 2 = 452

2. **Which is bigger: 768 or 786?**
**Answer**: 786
**Explanation**: 7 hundreds are same, compare tens: 6 < 8

3. **Write the number: 3 Thousands + 0 Hundreds + 4 Tens + 9 Ones**
**Answer**: 3049
**Explanation**: Add place values directly

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### Medium (2)
4. **Fill in the blank: 800 + ___ = 1000**
**Answer**: 200
**Explanation**: 1000 – 800 = 200

5. **Compare using > or <: 2390 ___ 2430**
**Answer**: 2390 < 2430
**Explanation**: Thousands are same, compare hundreds: 3 < 4

### Difficult (3)
6. **Write the number formed by: 2 Hundreds, 13 Tens, 7 Ones**
**Answer**: 337
**Explanation**: 13 Tens = 130; 2 Hundreds = 200; 200 + 130 + 7 = 337

7. **Mark these on a number line: 1027, 1043, 1069, 1084**
**Answer**: Use intervals of 10 from 1000 to 1100. Place each number correctly based on tens place.

8. **Create 3-digit numbers using digits 5, 0, 3, 8 that are less than 550**
**Answer**: 350, 305, 503, 530, 508, 385
**Explanation**: Ensure all are < 550 and made using allowed digits

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### Very Difficult (2)
9. **Find how many numbers are strictly between 7000 and 8000**
**Answer**: 999
**Explanation**: From 7001 to 7999 = 7999 – 7001 + 1 = 999

10. **Fill in the blanks: ___ + ___ = 1000, where one number is 497**
**Answer**: 497 + 503 = 1000
**Explanation**: 1000 – 497 = 503

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