2.Whole Numbers
The numbers 1,2, 3, are called natural numbers or counting numbers.Let us add one more number i.e., zero (0), to the collection of natural numbers. Now the numbers are 0,1,2, … These numbers are called whole numbers
We can say that whole nos. consist of zero and the natural numbers. Therefore, except zero all the whole nos. are natural numbers.
Facts of Whole numbers
1) The smallest natural number is 1.
2) The number 0 is the first and the smallest whole nos.
3) There are infinitely many or uncountable number of whole-numbers.
4) All natural numbers are whole-numbers.
5) All whole-numbers are not natural numbers. For example, 0 is a whole-number but it is not a natural number.
The first 50 whole nos. are
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,14, 15, 16, 17, 18, 19, 20, 21,
22, 23, 24, 25,26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50
Some other Important terms to remember
SUCCESSOR | The successor of a whole number is the number obtained by adding 1 to it. Clearly, the successor of 1 is 2; successor of 2 is 3; successor of 3 is 4 and so on. |
PREDECESSOR | The predecessor of a whole number is one less than the given number. Clearly, the predecessor of 1 is 0; predecessor of 2 is 1; predecessor of 3 is 2 and so on. The whole number 0 does not have any predecessor. |
1) Write the successor of
(a) (b) (c) (d)
2) Write the predecessor of
(a) (b) (c) (d)
Solution
1)
a)
b)
c)
d)
2)
a)
b)
c)
Properties of Whole Numbers
Closure Property
Closure property on Addition for Whole NumberClosure property on Multiplication for Whole Number
Closure property on subtraction of Whole number
Closure property on Division of Whole number
( Division by Zero is undefined)
In short
Closure Property | If a and b are any two whole numbers, then a+b, axb are also whole numbers. |
Commutative property
Commutativity property on Addition for Whole NumberCommutativity property on Multiplication for Whole Number
Commutativity property on subtraction of Whole number
but
So Whole number are not Commutative on SubtractionCommutativity property on Division of Whole number
but
So Whole Number are not Commutative on DivisionIn short
You can add two whole numbers in any order. You can multiply two whole numbers in
any order.
Commutative property | If a and b are any two whole numbers, then and |
Associative property
Associativity property on Addition for Whole NumberAssociativity property on Multiplication for Whole Number
or
So Whole number are Associative on MultiplicationAssociativity property on subtraction of Whole number
but
So Whole number are not Associative on SubtractionAssociativity property on Division of Whole number
but
So Whole Number are not Associative on DivisionSo in Short
If a, b and c are any two whole numbers, then (a+b)+c = a+(b+c) and (a×b)×c = a×(b×c).
Distributive property
If a, b and c are any two whole numbers, then Additive Identity
If a is any whole number, then .Example
Multiplicative Identity
If a is any whole number, thenExample
Multiplication by zero
If a is any whole number, then .Example