[O] how to avoid floating number problems with org-table for finances?

[Thomas Koch]

Hi,

I use a simple org-mode table to sum up the expenses and incomes of a small 
private project. Now I remembered that I should know as a programmer to NEVER 
EVER USE FLOATS FOR FINANCES!!!

But I did...

|                                        0.3 |
|                                        0.3 |
|                                        0.3 |
| 0.9000000000000000222044604925031308084726 |
#+TBLFM: @4$1=vsum(@address@hidden);%.40f

Do you know any quirck how I can continue using point notation but be sure 
that the numbers are added correctly? I think I'd need another vsum method 
that would

- find the number of decimal points of the most precise field
- parse all numbers to integers by filling up zeros at the end and ignoring 
the decimal point
- sum up
- write the result with a decimal point at the right position

Best regards,

Thomas Koch, http://www.koch.ro