What You’ll Learn

This chapter helps you understand:

• Reading and writing large numbers

• Place value in the Indian and International number systems

• Comparing numbers

• Forming and arranging numbers

• Estimation and rounding off

• Use of commas in large numbers

• Roman numerals

Key Concepts

1. Large Numbers up to 1 Crore

• Learn to read and write numbers as big as 1,00,00,000 (1 crore).

• Understand number names and numerals.

Example:
1,23,45,678 → One crore twenty-three lakh forty-five thousand six hundred seventy-eight

2. Place Value

• Understand the position of each digit in a number.

• Learn Indian and International place value systems.

Example:

• Indian: 56,78,912 → Fifty-six lakh seventy-eight thousand nine hundred twelve

• International: 5,678,912 → Five million six hundred seventy-eight thousand nine hundred twelve

3. Comparing Numbers

• Use signs: > (greater than), < (less than), = (equal to)

• Compare number of digits, then compare digit by digit.

Example:
982 > 829
56,700 < 76,500

4. Forming and Arranging Numbers

• Form the largest and smallest numbers using given digits.

• Arrange numbers in ascending (small to big) and descending (big to small) order.

Example:
Digits: 3, 7, 0
Smallest: 307 (not 037)
Largest: 730

5. Estimation

• Round off numbers to the nearest 10, 100, 1000, etc.

• Useful for quick calculations in daily life.

Rounding Rules:

• If the digit is 5 or more, round up.

• If less than 5, round down.

Example:
Rounding 847 to nearest 100 → 800
Rounding 875 to nearest 100 → 900

6. Using Brackets in Math

• Learn the BODMAS rule (Brackets, Orders, Division, Multiplication, Addition, Subtraction)

• Solve expressions with brackets.

Example:
(10 + 5) × 2 = 30
10 + (5 × 2) = 20

7. Roman Numerals

• Learn symbols like I, V, X, L, C, D, M

• Combine them to form numbers up to 100

Example:
VII = 7
XIV = 14
XL = 40
LXX = 70

Practice Problems

1. Write in figures: Ninety-eight lakh seventy thousand two hundred three.

2. Compare: 92,106 ___ 91,999

3. Form the largest 4-digit number using digits 3, 0, 7, 1.

4. Round off 1,48,723 to the nearest 1000.

5. Write the Roman numeral for 89.