Real Numbers 
DEFINITION. PROPERTIES. SYSTEM.
Real Numbers 
 A value that represents a quantity along a number 
line. 
 It is a set of undefined elements a, b, c, etc. or 
symbollically 
R = { a, b, c, … } 
 It has two basic operation: addition and 
multiplication.
Examples
Properties of Equality 
•Closure Property •Distributive Property 
•Commutative Property 
•Identity Property 
•Additive Identity 
•Multiplicative Identity 
•Associative Property 
•Inverse Property 
•Additive Inverse 
•Multiplicative Inverse
Properties of Equality 
Closure Property 
For any real number a, b € R, 
a+b € R and ab € R. 
Example: 
1+2=3 
R = {1,2,3}; 1,2,3 € R.
Properties of Equality 
Commutative Property 
For any real number a, b € R, 
a+b = b+a and ab = ba. 
Example: 
4 + 2 = 2 + 4 
4 x 2 = 2 x 4
Properties of Equality 
Associative Property 
For any real number a, b, c € R, 
(a + b) + c = a + (b + c) 
(ab)c = a(bc). 
Example: 
(4 + 2) + 3 = 4 + (2 + 3) 
(4 x 2) 3 = 4 (2 x 3)
Properties of Equality 
Distributive Property 
For any real number a, b, c € R, 
a (b + c) = ab + ac. 
Example: 
4 (5 + 3) = 4 (5) + 4 (3)
Properties of Equality 
Identity Property 
Additive Identity 
For any real number a € R, 
a+0=a. 
Example: 
4+0=4 
Zero is the identity element for 
addition or additive identity. 
Multiplicative Identity 
For any real number a € R, 
a . 1 =a. 
Example: 
4 . 1 =4 
One is the identity element for 
multiplication or multiplicative identity.
Properties of Equality 
Inverse Property 
Additive Inverse 
For any real number a, there is a 
real number called additive 
inverse of a denoted by “-a” such 
that a + (-a) = 1. 
Example: 
-(ab) + (ab) = 0 
Multiplicative Inverse 
For any real number a, there is a 
real number called multiplicative 
inverse of a denoted by “1/a” such 
that a . 1/a = 1. 
Example: 
4 . ¼ = 1
The Real Number System 
Real Numbers 
Rational Numbers 
Integers 
Positive 
Natural 
Numbers 
Fractions 
Zero Negative 
Irrational Numbers
Thank you! 
Presented by: 
Kenneth R. Wasawas 
BSED - 3

Real Numbers: Definition. Property. System

  • 1.
    Real Numbers DEFINITION.PROPERTIES. SYSTEM.
  • 2.
    Real Numbers A value that represents a quantity along a number line.  It is a set of undefined elements a, b, c, etc. or symbollically R = { a, b, c, … }  It has two basic operation: addition and multiplication.
  • 3.
  • 4.
    Properties of Equality •Closure Property •Distributive Property •Commutative Property •Identity Property •Additive Identity •Multiplicative Identity •Associative Property •Inverse Property •Additive Inverse •Multiplicative Inverse
  • 5.
    Properties of Equality Closure Property For any real number a, b € R, a+b € R and ab € R. Example: 1+2=3 R = {1,2,3}; 1,2,3 € R.
  • 6.
    Properties of Equality Commutative Property For any real number a, b € R, a+b = b+a and ab = ba. Example: 4 + 2 = 2 + 4 4 x 2 = 2 x 4
  • 7.
    Properties of Equality Associative Property For any real number a, b, c € R, (a + b) + c = a + (b + c) (ab)c = a(bc). Example: (4 + 2) + 3 = 4 + (2 + 3) (4 x 2) 3 = 4 (2 x 3)
  • 8.
    Properties of Equality Distributive Property For any real number a, b, c € R, a (b + c) = ab + ac. Example: 4 (5 + 3) = 4 (5) + 4 (3)
  • 9.
    Properties of Equality Identity Property Additive Identity For any real number a € R, a+0=a. Example: 4+0=4 Zero is the identity element for addition or additive identity. Multiplicative Identity For any real number a € R, a . 1 =a. Example: 4 . 1 =4 One is the identity element for multiplication or multiplicative identity.
  • 10.
    Properties of Equality Inverse Property Additive Inverse For any real number a, there is a real number called additive inverse of a denoted by “-a” such that a + (-a) = 1. Example: -(ab) + (ab) = 0 Multiplicative Inverse For any real number a, there is a real number called multiplicative inverse of a denoted by “1/a” such that a . 1/a = 1. Example: 4 . ¼ = 1
  • 11.
    The Real NumberSystem Real Numbers Rational Numbers Integers Positive Natural Numbers Fractions Zero Negative Irrational Numbers
  • 12.
    Thank you! Presentedby: Kenneth R. Wasawas BSED - 3