Sub Topics

Real numbers are used to measure the continuous values. A real number can be rational number or irrational number or it may be positive, negative or zero. It may also be algebraic or transcendental. Properties of Real Numbers that are used in various expressions and equations as follows: 1. The real numbers are dense in nature. Within two real numbers, lies an infinite other real numbers. 
Commutative property is an important part of mathematics, which is used to solve the problems of algebra. In a proper definition, real numbers are those numbers, that are not imaginary numbers. The real numbers did not have a name before imaginary numbers. Thatswhy, they were known as a real numbers. Commutative properties holds true under two operations which are addition and multiplication.
Commutative Property of Addition:
a + b = b + a
In the above given equation, it shows the commutative property of real numbers by addition. The commutative property of addition states that altering the arrangement of two numbers that are added does not make any modification in the final result. i.e, we can sum up numbers in any order but it does not affect the final result. In the general sense, in an additive equation, you can change the arrangement of real numbers anywhere. But, final result does not get affected through this shift of numbers. Here are some examples through which we can easily describe the commutative property of addition.
Example: 4 + 5 = 5 + 4 = 9
Commutative Property of Multiplication:
a * b = b * a
In the above given equation, it shows the commutative property of real numbers by multiplication. The commutative property of multiplication states that altering the arrangement of two numbers that are added does not make any modification in the final result i.e, we can multiply numbers in any arrangement. It wont affect the concluding result. In the general sense, in an multiplicative equation you can change the arrangement of real numbers anywhere. But, final result does not get affected through this shift of numbers. Here are some examples through which we can easily describe the commutative property of multiplication.
Example: 4 * 5 = 5 * 4 = 20
Solved Example
Solution:
Money Tom took from his mother = Rs. 50
Total money Tom had = 25 + 50 = Rs. 75
Money Terry had = Rs. 50
Money Terry took from his mother = Rs. 25
Total money Terry had = 50 + 25 = Rs. 75
We observe that in both the cases, we get the same result. Thus, they have the same amount of money.
This property of addition is called commutative property of addition. According to the commutative property of addition, the sum of any two given numbers remain the same, even if we change the order of their existence. So, a + b = b + a, where a and b are any numbers.
Solved Example
Solution:
Total money Jia earned = 10 * 5 = Rs. 50
We observe that in both the cases, we get the same result. Thus, they have same amount of money.
This property of multiplication is called commutative property of multiplication. According to the commutative property of multiplication, the product of any two given numbers remain the same, even if we change the order of their existence. So, a * b = b * a, where a and b are any numbers.
Associative property is an important part of mathematics, which is used to solve the problems of algebra. In a proper definition, real numbers are those numbers that are not imaginary numbers. The real numbers did not have a name before imaginary numbers. Thatswhy, they were known as real numbers. Associative properties holds true under two operations which are addition and multiplication.
Associative Property of Addition:
a + (b + c) = (a + b) + c
In the above given equation, it shows the associative property of real numbers by addition. The Associative Property of Addition states that altering the arrangement of brackets between the operators does not make any modification in the final result i.e, we can sum up numbers in any order but it does not affect the final result. Here are some examples through which we can easily describe the Associative property of addition.
Example: 3 + (4 + 5) = (3 + 4) + 5 = 12
Commutative Property of Multiplication:
a * (b * c) = (a * b) * c
In the above given equation, it shows the associative property of real numbers by multiplication. The associative property of multiplication states that altering the arrangement of brackets between the operators does not make any modification in the final result i.e, we can multiply numbers in any arrangement. It wont affect the concluding result. Here are some examples through which we can easily describe the associative property of multiplication.Example: 3 * (4 * 5) = (3 * 4) * 5 = 60 The Associative property of addition states that altering the arrangement of brackets between the operators does not make any modification in the final result i.e, we can sum up numbers in any order. But, it does not affect the final result.
Solved Example
Solution:
15 + 5 = 20
10 + 20 = 30
i.e, 10 + (15 + 5) = 30
Calculation done by the cashier:
10 + 15 = 25
25 + 5 = 30
i.e, (10 + 15) + 5 = 30
We observe that in both the cases, we get the same result.
This property of addition is called associative property of addition. According to the associative property of addition, the sum of any three given numbers remain the same, even if we change the arrangement of brackets between the operators. So, a + (b + c) = (a + b) + c where a, b and c are any numbers.
a * (b * c) = (a * b) * c
The associative property of multiplication can be explained by the following examples:
Examples :
2 * (3 * 4) = (2 * 3) * 4 = 24
4 * (2 * 6) = (4 * 2) * 6 = 48
1 * (6 * 3) = (1 * 6) * 3 = 18
3 * (7 * 5) = (3 * 7) * 5 = 105
2 * (5 * 8) = (2 * 5) * 8 = 80
We observe that in both the cases, we get the same result for all the above examples.
This property of multiplication is called associative property of multiplication. According to the associative property of multiplication, the product of any three given numbers remains the same, even if we change the arrangement of brackets between the operators. So, a * (b * c) = (a * b) * c where a, b and c are any numbers.
The distributive property is a property for binary operations with at least two operands. This property comes in case when any expression has both the addition and multiplication operations. This is also known as the distribution property of multiplication over addition operation. According to this property of multiplication over addition, if any number or term is multiplied by the terms covered by the parenthesis, then we need to multiply that term to all the terms inside the parenthesis.
 5 * (4 + 3) = (5 * 4) + (5 * 3) = 35
 2 * (3 + 6) = (2 * 3) + (2 * 6) = 18
According to the density property, the real numbers are infinite. Between two real numbers, lies an infinite real numbers. For example, between 3 and 4, lies $\frac{3}{2}$, $\frac{3}{4}$, $\frac{3}{5}$, $\frac{3}{7}$, $\frac{3}{8}$, $\frac{3}{11}$, ....... etc. This means that real numbers cannot be counted and there can exist uncountable number of real numbers in the number system.
To prove that the real numbers are dense, follow the steps given below:
 Consider any two real numbers say $\frac{3}{4}$ and $\frac{3}{8}$.
 Add them. $\frac{3}{4}$ + $\frac{3}{8}$ = $\frac{9}{8}$
 Divide it by 2 and it gives the midvalue of $\frac{3}{4}$ and $\frac{3}{8}$. So, $\frac{9}{16}$ lies between $\frac{3}{4}$ and $\frac{3}{8}$.
 Similarly, we can find the midvalue of $\frac{3}{4}$ and $\frac{9}{16}$ and this will continue.
Real numbers are those numbers that are not imaginary numbers. The real numbers did not have a name before imaginary numbers. Thatswhy, they were known as real numbers. Identity properties holds true under two operations which are addition and multiplication.
Identity Property of Addition:
a + 0 = a
The above equation shows the identity property of addition. The identity property of addition for real numbers states that, there exist a real number 0 such that, if we add any real number to that number, the number remains unchanged.
Example: 4 + 0 = 4
Here, we observe that, when 0 is added to a real number 4, the result remains unchanged. So, we say that 0 is additive identity.
Identity Property of Multiplication:
a * 1 = a
The above equation shows the identity property of multiplication. The identity property of multiplication for real numbers states that, there exists a real number 0 such that if we multiply any real number to that number, the number remains unchanged.
Example: 4 * 1 = 4
Here, we observe that, when 0 is multiplied to a real number 4, the result remains unchanged. So, we say that 0 is the multiplicative identity. The identity property of addition for real numbers states that, there exist a real number 0 such that, if we add any real number to that number, the number remains unchanged.
The identity property of addition can be explained by the following examples:
 4 + 0 = 4
 2.7 + 0 = 2.7
 11 + 0 = 11
 $\frac{3}{4}$ + 0 = $\frac{3}{4}$
The identity property of multiplication can be explained by the following examples:
 4 * 1 = 4
 2.7 * 1 = 2.7
 11 * 1 = 11
 $\frac{3}{4}$ * 1 = $\frac{3}{4}$