NUMBER SYSTEMS

  • -6
  • -5
  • -4
  • -3
  • -2
  • -1
  • 0
  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
DigitsThe symbols used to represent a number are called digits. The name "digit" comes from the fact that the ten digits (Latin digiti meaning fingers) of the hands correspond to the ten symbols of the common base 10 numeral system, i.e. the decimal digits.

0 1 2 3 4 5 6 7 8 9
In order to represent any numbers, we use ten symbols 0, 1, 2, 3, 4, 5, 6, 7, 8 and 9. These ten symbols are called digits or figures.
NumeralA group of digits denoting a number is called a numeral. For example, 456, 73456, 3487 etc.
Single digit number: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
Two digits number: 10, 11, 12, .................99
Three digits number: 100, 101, 102, ............999
Four digits number: 1001, 1002, 1003, ..........9999
Five digits number: 10001, 10002, ..............99999

Greatest single digit number + 1 = smallest 2-digit number
Greatest 2-digit number + 1 = smallest 3-digit number
Greatest 3-digit number + 1 = smallest 4-digit number
Greatest 4-digit number + 1 = smallest 5-digit number
Greatest 5-digit number + 1 = smallest 6-digit number
NotationThe method of representing a number in digits or figures is called notation.
NumerationThe method of expressing a number in words is called numeration.
SuccessorThe number which comes immediately after a particular number is called its successor.
5 6 Successor
The successor of a number is obtained by adding 1 to it. For example, the successor of 0 is 1; successor of 1 is 2; successor of 2 is 3 and so on.
PredecessorThe number which comes just before a particular number is called its predecessor.
8 9 Predecessor
The predecessor of a number is obtained by substracting 1 from it. For example, the predecessor of 2 is 1; predecessor of 1 is 0; predecessor of 3 is 2 and so on.
PeriodIn decimal number system, the value of a digit depends on its place value, or positional value, in the number. Each place has a value of 10 times the place to its right.

Ten Thousands Thousands Hundreds Tens Ones
T Th Th H T O
10000 1000 100 10 1
A number in standard form is separated into groups of three digits using commas. Each of these groups is called a period.

In Indian System of Numeration numbers are seperated into groups of two digits using commas, therefore in this system period is of group of two digits.
Commutative Property An operation is commutative if changing the order of the operands does not change the result. It is expressed as,
a + b = b + a
4 + 5 = 5 + 4
9 = 9
When we change the order of the numbers that we are adding the sum remains the same. This shows addition is commutative.
abba
8338
5–5
When we change the order of the numbers that we are subtracting the result changed. This shows subtraction is not commutative.
a b = b a
4 5 = 5 4
20 = 20
When we change the order of the numbers that we are multiplying the product remains the same. This shows multiplication is commutative.
a ÷ bb ÷ a
8 ÷ 44 ÷ 8
2
1/2
When we change the order of the numbers that we are dividing the result changed. This shows division is not commutative.
Associative Property An operation in which changing the order of the operation does not affect the result is called associative property. Consider the following equations:

a + (b + c) = (a + b) + c
3 + (5 + 6) = (3 + 5) + 6
3 +  11  =    8 + 6
14  = 14

Even though the parentheses were rearranged on each line, the values of the expressions were not altered. Since this holds true when performing addition. This shows addition is associatative.
Subtraction:
a – (bc) ≠ (ab) – c
3 – (76) ≠ (37) – 6
31– 46
2–10

This shows subtraction doesn’t follow the associative property. Regrouping the numbers resulted in two different answers. This shows subtraction is not associatative.
Multiplication:
a (b c) = (a b) c
3 (5 6) = (3 5) 6
3 30    = 15 6
90          = 90

Even though the parentheses were rearranged on each line, the values of the expressions were not altered. Since this holds true when performing multiplication. This shows multiplication is associatative.
Division:
a ÷ (b ÷ c) ≠ (a ÷ bc
18 ÷ (6 ÷ 3) ≠ (18 ÷ 6) ÷ 3
18 ÷ 23 ÷ 3
91

Division doesn’t follow the associative property. Regrouping the numbers resulted in two different answers. This shows division is not associatative.
Distributive Property An operation in which multiplying the sum by a number gives the same result as first multiplying each addend by the number and then adding the products is called Distributive Property. Consider the following equations:

a (b + c) = ab + ac
             3 (5 + 6) = (3 5) + (3 6)
3 11    = 15 + 18
33   = 33

So the "3" can be "distributed" across the "5+6" into 3 times 5 and 3 times 6. This shows multiplication is distributive over addition.
Subtraction:
a (bc) = abac
             3 (56) = (3 5) – (3 6)
3 1 = 15 – 18
3 = 3

So the "3" can be "distributed" across the "5 – 6" into 3 times 5 and 3 times 6. This shows multiplication is distributive over subtraction.
Additive Identity An operation in which adding zero to any number results same number is called additive identity. Consider the following equations:
0 + a = a
0 + 5 = 5

If 0 is added to 5, result is same 5.
Zero is an additive identity for Natural Numbers, Whole Numbers, Integers, Rational numbers, Irrational numbers, Real Numbers and Complex numbers.
Multiplicative Identity An operation in which a number is multiplying by 1 results same number is called multiplicative identity. Consider the following equations:
1 a = a
1 5 = 5

When 5 is multiplied by 1 yields the same result 5.
1 is multiplicative identity for Natural Numbers, Whole Numbers, Integers, Rational numbers, Irrational numbers, Real Numbers and Complex numbers.
Additive Inverse An operation in which a number added to it yields zero is called additive inverse. This number is also known as the opposite number. The opposite to a positive number is negative, and the opposite to a negative number is positive. Zero is the additive inverse of itself. Consider the following equations:
a + ( -a) = 0
5 + ( -5) = 0

Here opposite of 5, i.e. -5 added to 5 yields 0.
Multiplicative Inverse An operation in which a number multiplied by it yields 1 is called multiplicative inverse. This number is also known as the reciprocal of same number. For example reciprocal of a is denoted by
1 / a
or a-1. Consider the following equations:
a(
1 / a
) = 1, Where a ≠ 0

Here a is multiplied by reciprocal of a yields 1. When we multiply a number by its "Multiplicative Inverse" we get 1.
Contact us
Email Us                                                  

Email us for a quick response...