Mathematica supports arbitrary precision and exact numbers, but it can also operate using normal machine-precision floating point numbers of the kind used in Excel and many other programs. When using machine-precision numbers, all the usual issues around floating-point arithmetic apply, including the possibility that precision might decline in certain calculations.

Useful links

  • N, the function that turns exact numbers (Integers and Rationals) into Real numbers. Converts numbers at any position in an expression thus it works on vectors and matrices too.
  • Tutorial on numerical precision covering among other things Precision and Accuracy.
  • NumberForm changes the displayed version of the number without actually changing its underlying precision or accuracy.

Example questions

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