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Mathematica Teacher's Edition

Built-in Functions

Mathematical Functions

Numerical Functions

Ceiling

Ceiling[x] gives the smallest integer greater than or equal to x.

Mathematical function (see Section A.3.10).
Examples: Ceiling[2.4]; Ceiling[2.6]; Ceiling[-2.4]; Ceiling[-2.6].
Ceiling[x] can be entered in StandardForm and InputForm as x , lc x rc or \[LeftCeiling] x \[RightCeiling].
Ceiling[x] returns an integer when x is any numeric quantity, whether or not it is an explicit number.
Example: Ceiling[Pi^2].
For exact numeric quantities, Ceiling internally uses numerical approximations to establish its result.
See The Mathematica Book on the web: Section 3.2.2.
See also: Floor, IntegerPart, Round, Chop.