Class 5 Notes - Number names and Number Sense (7 and 8 digit numbers)

Introduction

Numbers play a crucial role in mathematics and daily life. In this chapter, we will explore number names and number sense for 7-digit and 8-digit numbers.

Understanding Large Numbers

In the Indian numbering system, large numbers are represented using place values such as Lakhs and Crores. In the International system, they are represented using Millions.

Place Value Chart

Indian Place Value System

The Indian place value system groups digits into ones, tens, hundreds, thousands, lakhs, and crores.

  • 1 (One)
  • 10 (Ten)
  • 100 (Hundred)
  • 1,000 (Thousand)
  • 10,000 (Ten Thousand)
  • 1,00,000 (One Lakh)
  • 10,00,000 (Ten Lakh)
  • 1,00,00,000 (One Crore)

International Place Value System

In the International system, large numbers are grouped as follows:

  • 1 (One)
  • 10 (Ten)
  • 100 (Hundred)
  • 1,000 (Thousand)
  • 10,000 (Ten Thousand)
  • 100,000 (Hundred Thousand)
  • 1,000,000 (One Million)
  • 10,000,000 (Ten Million)

Reading and Writing Large Numbers

To read and write large numbers, follow these steps:

  • Start from the left and group the digits according to the place value chart.
  • Use commas to separate different periods (as per the Indian or International system).
  • Read each group of digits along with their place value.

Examples

Indian System

7-digit number: 25,43,678 (Twenty-five lakh forty-three thousand six hundred seventy-eight)

8-digit number: 5,34,76,891 (Five crore thirty-four lakh seventy-six thousand eight hundred ninety-one)

International System

7-digit number: 2,543,678 (Two million five hundred forty-three thousand six hundred seventy-eight)

8-digit number: 53,476,891 (Fifty-three million four hundred seventy-six thousand eight hundred ninety-one)

Comparison of Numbers

To compare numbers, check the number of digits first. If they have the same number of digits, compare place values from left to right.

Expanding Numbers

Numbers can be expanded according to their place values. For example:

5,34,76,891 = 5,00,00,000 + 30,00,000 + 4,00,000 + 70,000 + 6,000 + 800 + 90 + 1

Conclusion

Understanding large numbers, their names, and place values helps in mathematical calculations and real-life applications.