A rational number is a real number that can be written as a quotient of two integers.

A rational number is a number that can be expressed as a fraction p/q where p and q are integers and q!=0. A rational number p/q is said to have numerator p and denominator q. Numbers that are not rational are called irrational numbers. The real line consists of the union of the rational and irrational numbers. The set of rational numbers is of measure zero on the real line, so it is "small" compared to the irrationals and the continuum. The set of all rational numbers is referred to as the "rationals, " and forms a field that is denoted Q. Here, the symbol Q derives from the German word Quotient, which can be translated as "ratio, " and first appeared in Bourbaki's Algèbre (reprinted as Bourbaki 1998, p. 671).

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Rationals

high school level (California grade 7 standard)