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Mathematica Teacher's Edition

Built-in Functions

Numerical Computation

Number Representation

Rational

Rational is the head used for rational numbers.

You can enter a rational number in the form n/m.
The pattern object _Rational can be used to stand for a rational number. It cannot stand for a single integer.
You have to use Numerator and Denominator to extract parts of Rational numbers.
See The Mathematica Book on the web: Section 3.1.1.
See also: Rationals, Integer, Numerator, Denominator.

Further Examples