I think I've found a solution with the rounding problems when using CDBL. I can reformat a formula in such a way that it does not require doubles but only integers. This method could be used for those permutations where fractions might show up as interim results.
code:
                  3
(3+3/7)*7 = ( 3 + - ) * 7
                  7

              3 * 7 + 3
          = ( --------- ) * 7
                  7

          = ( 3 * 7 + 3 ) / 7 * 7

          = ( 3 * 7 + 3 ) * 7 / 7

          = 24

or generic

(a+b/c)*d = ( a * c + b) * d / c
By essentially moving the division I end up with an integer devidied by an integer.

[ 17. September 2002, 14:16: Message edited by: sealeopard ]
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