In mathematics, the set of real numbers (denoted by ℝ) includes both rational numbers (positive, negative and zero) and irrational numbers. A real number can be a rational number or an irrational number. The rational numbers are those that can be expressed as the quotient of two integers. -7 / 9 = -0.777 -2 / 3 = -0.666 Both are rational numbers since they are periodic from the first decimal
