# FP Math Caution (The GNU Awk User’s Guide)

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### 16.4 Floating-Point Arithmetic: Caveat Emptor!

Math class is tough!

— *Teen Talk Barbie, July 1992*

This section provides a high-level overview of the issues involved when doing lots of floating-point arithmetic.100 The discussion applies to both hardware and arbitrary-precision floating-point arithmetic.

CAUTION:The material here is purposely general. If you need to do serious computer arithmetic, you should do some research first, and not rely just on what we tell you.

• Inexactness of computations | Floating point math is not exact. | |

• Getting Accuracy | Getting more accuracy takes some work. | |

• Try To Round | Add digits and round. | |

• Setting precision | How to set the precision. | |

• Setting the rounding mode | How to set the rounding mode. |

#### Footnotes

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There is a very nice paper on floating-point arithmetic by David Goldberg, “What Every Computer Scientist Should Know About Floating-Point Arithmetic,” ACM Computing Surveys **23**, 1 (1991-03): 5-48. This is worth reading if you are interested in the details, but it does require a background in computer science.