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:
- Height below the surface of the sea level
- Spending
- Temperature below 0°C
- Debit amount
- 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.