This seems to work: import Data.Ratio cf :: [Integer] -> Rational cf (x:[]) = toRational x cf (x:xs) = toRational x + (1 / cf xs) Hugs> :load cf.hs Main> cf [1,2,6,5] 98 % 67 Main> cf [2,3] 7 % 3 Main> Thanks, guys! Michael --- On Sun, 3/29/09, Luke Palmer <lrpalmer@gmail.com> wrote: From: Luke Palmer <lrpalmer@gmail.com> Subject: Re: [Haskell-cafe] type Rational and the % operator To: "michael rice" <nowgate@yahoo.com> Cc: "Ryan Ingram" <ryani.spam@gmail.com>, haskell-cafe@haskell.org Date: Sunday, March 29, 2009, 12:23 AM 2009/3/28 michael rice <nowgate@yahoo.com> Still the same problem. The book says the answer is supposed to be an exact 98/67. Michael import Data.Ratio cf :: [Integer] -> Rational cf (x:xs) = (x % 1) + (1 % (cf xs)) cf (x:[]) = x % 1 cf [] = 0 % 1 Use (/) for division: cf :: [Integer] -> Rationalcf (x:xs) = toRational x + 1 / cf xscf [x] = toRational x cf [] = 0 Luke