NumberForm (Built-in Mathematica Symbol)

NumberForm[expr, n] prints with approximate real numbers in expr given to n-digit precision.

MachineNumberQ (Built-in Mathematica Symbol)

MachineNumberQ[expr] returns True if expr is a machine-precision real or complex number, and returns False otherwise.

AlgebraicIntegerQ (Built-in Mathematica Symbol)

AlgebraicIntegerQ[a] yields True if a is an algebraic integer, and yields False otherwise.

Algebraic Calculations (Mathematica Overview)

Symbolic Computation Values for Symbols Transforming Algebraic Expressions

$MaxNumber (Built-in Mathematica Symbol)

$MaxNumber gives the maximum arbitrary-precision number that can be represented on a particular computer system.

RootApproximant (Built-in Mathematica Symbol)

RootApproximant[x] converts the number x to one of the "simplest" algebraic numbers that approximates it well.RootApproximant[x, n] finds an algebraic number of degree at ...

$NumberMarks (Built-in Mathematica Symbol)

$NumberMarks gives the default value for the option NumberMarks, which specifies whether ` marks should be included in the input form representations of approximate numbers.

IsolatingInterval (Built-in Mathematica Symbol)

IsolatingInterval[a] gives a rational isolating interval for the algebraic number a.IsolatingInterval[a, dx] gives an isolating interval of width at most dx.

$MinMachineNumber (Built-in Mathematica Symbol)

$MinMachineNumber is the smallest positive machine-precision number that can be used on a particular computer system.

NumberPadding (Built-in Mathematica Symbol)

NumberPadding is an option for NumberForm and related functions which gives strings to use as padding on the left- and right-hand sides of numbers.