Convert any number to corresponding word

Question

This is a wild one: can anyone write a code that converts a number into the corresponding word? e.g.:

4 -> 'four'
31 -> 'thirty-one'

and so on. Obviously, it is not enough to build an array in which you can store the numbers and the word associated with it and then just print instead of the number the stored word. What complicates matters more, are numbers like 11 ('eleven'). I intend to use it for numbering equations. So, anybody up to it?

Answer 1

You can use the fmtcount package to achieve that:

\documentclass{minimal}
\usepackage{fmtcount}

\begin{document}

4: \numberstringnum{4}

31: \numberstringnum{31}

\end{document}

Use \Numberstringnum and \NUMBERstringnum respectively for capitalized and full-caps versions.

Answer 2

The moreenum package already does this as well.

\documentclass{article}
\usepackage{moreenum}
\newcounter{mycounter}
\renewcommand{\themycounter}{\Nthwords{mycounter}}
\begin{document}

\setcounter{mycounter}{11}
\themycounter

\setcounter{mycounter}{470}
\themycounter

\end{document}

Result:

Use \nthwords for lowercase. I think in the next version of the package, these will change to \nwords and \Nwords.

Answer 3

fmcount only works with numbers up to 100,000. For larger numbers, you will need to use numname which borrows the code from the memoir class. From what I recall, this can deal with bigger numbers. Neither the readme nor the package documentation actually tells you what the commands to use are, so here they are:

• \numtoname turns a number into lowercase words (e.g. one)
• \numtoName as above, but the first letter is capitalised
• \NumToName as above but all words are capitalised
• \ordinaltoname turns a number into lc ordinal (e.g. first)
• \ordinaltoName as above but first letter capitalised
• \OrdinalToName as above but all words capitalised

This package seems to manage all numbers up to TeX's limit of 2147483647. (numname helfully informs me that this is: two billion, one hundred and forty-seven million, four hundred and eighty-three thousand, six hundred and forty-seven)