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# Class 2 Number System

Introduction to 4-Digit Numbers

4-Digit Number in Words

Expanded Notation

Place Value

Comparision of Numbers

Ascending Order

Descending Order

Successor

Predecessor

Number System Test

Number System Worksheet

## Introduction to 4-Digit Numbers

In class I, we have learnt up to 3-digit number. We know smallest 3-digit number is 100 and largest 3 digit number is 999.

If we add 1 to largest 3-digit number, then we will get the smallest 4 digit number.
999 + 1 = 1000
So, 1000 is the smallest 4-digit number.

Few 4-digit numbers are given below.

2458 – Two thousand four hundred fifty eight
5769 – Five thousand seven hundred sixty nine
6245 – Six thousand two hundred forty five

## 4-Digit Number in Words

We can write 4-digit numbers in word format.

1245 – One thousand two hundred forty five

1764 – One thousand seven hundred sixty four

2126 – Two thousand one hundred twenty six

5472 – Five thousand four hundred seventy two

6986 – Six thousand nine hundred eighty six

9035 – Nine thousand thirty five

9967 – Nine thousand nine hundred sixty seven

9999 – Nine thousand nine hundred ninety nine

9999 is the greatest 4-digit number.

## Expanded Notation

We can write any number by expanding it into ones, tens, hundred and thousand. Let’s have a look at some examples.

1635 = 1 thousand 6 hundred 3 tens 5 ones = 1000 + 600 + 30 + 5

2437 = 2 thousand 4 hundred 3 tens 7 ones = 2000 + 400 + 30 + 7

4586 = 4 thousand 5 hundred 8 tens 6 ones = 4000 + 500 + 80 + 6

8745 = 8 thousand 7 hundred 4 tens 5 ones = 8000 + 700 + 40 + 5

9999 = 9 thousand 9 hundred 9 tens 9 ones = 9000 + 900 + 90 + 9

## Place Value

Number Thousands Hundreds Tens Ones
1567 1 5 6 7
5246 5 2 4 6
6587 6 5 8 7   ## Comparision of Numbers

We have already known the method of getting the greater number between two 2-digits numbers. Here we shall learn the method of knowing the greater number between two given 3/4 digits numbers.

Rule no. 1 – The number which is having more digits is greater than the number having a smaller number of digits.

Example.456 > 99, 8745 > 987

Rule No. 2 – If the two numbers have the same number of digits then we compare the extreme left digits and decide which is larger.If the extreme left digits of the two numbers are same, we keep on comparing the next digits on the right.

Example.5894 > 5678, 85678 > 85572 & 9873 > 9532

## Ascending Order

Arranging numbers from Smaller to Greater is known as ascending Order.

Example 1. Write the following numbers in ascending order.
7535, 8538, 8987, 675, 45

Solution. Smallest number is 45, the next number which is greater than 45 is 675.
The other numbers greater than 675 in order are 7535, 8538 and 8987.
All the given numbers written in ascending order are:
45, 675, 7535, 8538, 8987.

## Descending Order

Arranging numbers from greater to smaller is known as descending order.

Example 2. Write the following numbers in descending order.
565, 7265, 8440, 4250, 2226

Solution. In the above numbers greatest number is 8440. The next number smaller than 8440 is 7265.
The other number smaller than 7265 in order are 4250, 2226, 565.
All the given numbers written in descending order are:
8440, 7265, 4250, 2226, 565.

## Successor

Number that comes just after a number is called its successor.

Number Method Successor
285 285+1 286
5039 5039+1 5040
9885 9885+1 9886

We can get the successor of a number by adding 1 to the given number.

## Predecessor

Number that comes just before a number is called its predecessor.

Number Method Predecessor
285 285-1 284
5039 5039-1 5038
9885 9885-1 9884

We can get the predecessor of a number by subtracting 1 from the given number.

## Number System Test

Number System Test - 1

Number System Test - 2

## Class-2 Number System Worksheet

Number System Worksheet - 1

Number System Worksheet - 2

Number System Worksheet - 3