>> Why on earth do you need so many sig figs?
>
>> To put some perspective on this, 50 sig figs lets you express the mass of the observable universe accurate to about 200kg.
>
>Well, it's for a client. Mine is not to question why...I just wondered how hard it was to do.
>
>Actually he only needs 34 places so that should localize it to just our galaxy. :)

If you know how to add, subtract, multiply and divide on paper, you already know the algorithms you have to teach the computer. Nothing extremely difficult, but some detail work is required.

I think I would save the numbers as character or memo. For calculation purposes, convert to an array, and have a few additional properties for each number, like: is it negative, position of decimal point, or so.

Come to think of it, I find this an intriguing problem, other people have asked already, and I might try it eventually. But don't count on this soon.

There is a file in the download section, but I think it only does addition and subtraction.

Hilmar.