Introduction to Integers

Introduction to Integers 

 Natural Numbers

  • Set of counting numbers is called the Natural Numbers.

Whole Numbers

  • Set of Natural numbers plus Zero is called the Whole Numbers

Note: All natural Number are whole number but all whole numbers are not natural numbers

Example :

2 is Natural Number

-2 is not a Natural number

0 is a Whole number

Negative Numbers

  • The numbers with a negative sign and which lies to the left of zero on the number line are called negative numbers.
  • Some of the situations where we use the negative numbers are as follows:
  1. Height below the surface of the sea level
  2. Spending
  3. Temperature below 0°C
  4. Debit amount
  5. Outstanding dues.

Integers

  • Collection of all positive and negative numbers including zero are called integers. 

  • I =  …, – 4, – 3, – 2, – 1, 0, 1, 2, 3, 4, … 

  • Zero is neither a positive nor a negative integer.

Representing Integers on the Number Line

  • Draw a line and mark a point as 0 on it

  • Points marked to the left (-1, -2, -3, -4, -5, -6) are called negative integers.

  • Points marked to the right (1, 2, 3, 4, 5, 6) or (+1, +2, +3, +4, +5, +6) are called positive integers.

Ordering of Integers

  • On a number line, the number increases as we move towards right and decreases as we move towards left.
  • Hence, any number on the right side on the number line is greater than the number on its left.

Example

  5 is to the right of  2   so 5>2. 

  4 is to the right of -2,  so 4>-2.

-4 is to the left of  -1,    so -4 < -1. 

Absolute value of an integer

  • Absolute value of an integer is the numerical value of the integer without considering its sign.

  • Example: Absolute value of -7 is 7 and of +7 is 7.