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# Class 4 Number System

Recap of Number System

Place Value of 6-Digit Number

Expanded Forms of Six Digit Numbers

Comparison of Two Numbers

Ascending Order

Descending Order

Indian Number System

International Number System

Number System Test

Number System Worksheet

## Recap of Number System

In class III, we learnt up to 5 digits numbers.

Smallest 5-digit number is 10000, it is read as ten thousand.

Largest 5-digit number is 99999, it is read as ninety nine thousand nine hundred ninety nine.

One more than 99999 = 99999 + 1 = 100000

100000 read as one lakh. It is the smallest six digit number.

One more than 100000 = 100000 + 1 = 100001

100001 is read as one lakh one.

100010 is read as one lakh ten.

100099 is read as one lakh ninety nine.

100201 is read as one lakh two hundred one.

105001 is read as one lakh five thousand one.

109999 is read as one lakh nine thousand nine hundred ninety nine.

152065 is read as one lakh fifty two thousand sixty five.

999999 is the greatest six digit number.

## Place Value of 6-Digit Number

Place value table and some examples

Number Lakh Ten-Thousands Thousands Hundreds Tens Ones
100251 1 0 0 2 5 1
106972 1 0 6 9 7 2
675231 6 7 5 2 3 1
999999 9 9 9 9 9 9

## Expanded Forms of Six Digit Numbers

In class III, we learnt how to write 4/5 digit number in expanded form. Here we will learn how to write 6 digit
number in an expanded form.

Example 1. Write 654213 in expanded form.

Solution.
654213 = 600000 + 50000 + 4000 + 200 + 10 + 3

Example 2. Write 405032 in expanded form.

Solution.
405032 = 400000 + 0 + 5000 + 0 + 30 + 2
= 400000 + 5000 + 30 + 2

## Comparison of Two Numbers

In class III, we have learnt how to compare two numbers. We will follow the same rules for comparing 6 digit numbers.

Rule 1. Number which contains more digits is greater than the number having less digits.

Rule 2. When two numbers contain same digits then we compare left most digits of both the numbers.

Number which is having greater digit should be considered as larger number. If the left most digits of both the numbers are same, then we compare the next digits to the right. This process continues till we get a greater digit to decide which number is greater.

Example 1. Which number is greater? 665785 and 676865

Solution. For both the numbers lakh place is having digit 6. We can not decide which number is greater by comparing lakh place.
Now, let’s consider ten thousand place.
665785 has 6 in ten thousand place.
676865 has 7 in ten thousand place.
We know 7 is greater than 6.
So, 665785 is less than 676865.

## Ascending Order

Ascending order means, writing a given group of numbers in increasing order. Let’s have a look at some examples.

Example 1. Arrange the below given numbers in ascending order.

506780, 500789, 506098, 567893
Solution. 500789, 506098, 506780, 567893

## Descending Order

Descending order means writing a given group of numbers in decreasing order. Let’s have a look at few examples.

Example 1. Arrange the below given numbers in descending order.

156798, 156780, 155634, 165020
Solution. 165020, 156798, 156780, 155634

## Indian Number System ## International Number System ## Number System Test

Number System Test - 1

Number System Test - 2

## Class-4 Number System Worksheet

Number System Worksheet - 1

Number System Worksheet - 2

Number System Worksheet - 3

Number System Worksheet - 4