Properties of Whole numbers

The sum of any two whole numbers is a whole number? This property of whole number is referred to as

Property 3 Each whole number (except zero) has one and only one predecessor.The predecessor of a whole number just on its on the the number line.

Property 2 Each whole number has one and only one successor.The successor of a whole number is the whole number just on its right on the number line.Also 0 is not the successor of any whole number.

Property 4 The subtraction of whole numbers is not associative.That is if abc are three whole numbers then in general a-(b-c) is not equal to (a-b)-c

Property 2 The subtraction of whole numbers is not commutative that is if a and b are two whole numbers then in general a-b is not equal to (b-a)

On adding 9 to the twice of a whole number gives 31. the whole number is

Representation of whole numbers on numbers line

Property 5 Every whole number on the number line is less than every whole number on its right.

Property 4 Every whole number on the number line is greater than every whole number on its left.

Find the sum, using the associative property of addition of whole numbers. 73 + 47 + 53