There are now several comprehensive web applications, stand-alone computer programs and computer algebra functions that, given a floating point number such as 6.518670730718491, can return concise nonfloat constants such as 3 arctan 2 + ln 9 + 1, that closely approximate the float. Examples include AskConstants, Inverse Symbolic Calculator, the Maple identify function, MESearch, OEIS, RIES, and WolframAlpha. Usefully often such a result is the exact limit as the float is computed with increasing precision. Therefore these program results are candidates for proving an exact result that you could not otherwise compute or conjecture without the program. Moreover, candidates that are not the exact limit can be provable bounds, or convey qualitative insight, or suggest series that they truncate, or provide sufficiently close efficient approximations for subsequent computation. This article describes some of these programs, how they work, and how best to use each of them. Almost everyone who uses or should use mathematical software can benefit from acquaintance with several such programs, because these programs differ in the sets of constants that they can return.

翻译：现在有几种全面的网络应用程序、独立计算机程序和计算机代数功能,这些功能,考虑到一个浮点数,如6.6188770707318491,可以返回精确的非浮点常数,如3arctan 2 + in 9+ 1,这些常数接近浮点数。例子包括AskConstants、反光计算器、Maple识别功能、MESearch、OEIS、RIES和WolframAlpha。这种结果通常有用,因为浮点数的计算越来越精确。因此,这些程序的结果可以用来证明一个确切的结果,证明你无法在没有程序的情况下进行计算或预测。此外,非精确限制的候选人可以是可剖析的界限,或传达质量洞察力,或建议他们转动的序列,或为随后的计算提供足够高效的近似值。这篇文章描述了其中一些程序,如何运作,以及如何最好地使用其中每一个程序。几乎所有使用或应该使用数学软件的人都可以从了解若干这样的程序中获益,因为这些程序在他们可以返回的恒定数中是不同的。