In mathematics, a rational number is a number that can be expressed as the quotient or fraction p q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number. 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. For example, one third in decimal form is 0.33333333333333 (the threes go on forever). Chapter 2 explains students about the introduction of rational numbers, representation of rational numbers on the number line, comparing rational numbers and problems on rational numbers.