Rational numbers are numbers that can be expressed as a fraction or part of a whole number. (Examples: -7, 2/3, 3.75) Irrational numbers are numbers that cannot be defined as a fraction or ratio of two integers. There is no finite way to express them. (Examples: root2, pi, e). A rational number is a number that can be express as the ratio of two integers. A number that cannot be expressed that way is irrational. However, numbers like root2 are irrational because it is impossible to express root2 as a ratio of two integers. Numbers that can be defined as a ratio of two number (p/q form) are termed as a rational number. Numbers that cannot be described as a ratio of two numbers are termed as an irrational number. Chapter 1 takes the students to the different sets of numbers, the Rational and Irrational Numbers.