The numbers which exists as Real Numbers includes Whole Number (0,1, 2, 3, etc), natural numbers (1, 2, 3, etc), integers(-1, 0, 1, 2, etc), irrational numbers ( pie, √2, etc), and Rational Numbers ( 0.33, 1/3, 1.11, etc). Imaginary and infinity are not real numbers. Rational numbers are numbers represented by dividing one number from other number i.e. numerator and denominator. For example: a/b, 1/2, 0.50, etc. Real rational numbers are those numbers which are real and rational both. For example: A number 2 is also a real number as well as fraction. Because 2 can also be written as 2/1. 5/3 is also a real rational number, as it comes in a real number line and also a fraction. 0.75 is also a real rational number, as we can also represent it as 75/100 = 3/4. -sqrt(81) = -9 is also a real rational number and also an Integer.