I have uploaded a new package to Hackage implementing two methods for rounding a set of numbers while maintaining their sum. Useful applications are elections of parliaments and rounding percentages. E.g. Prelude> Apportionment.largestRemainderScaled 100 [1,2,3 :: Double] [17,33,50] Prelude> Apportionment.largestRemainderScaled 100 [1,1,1 :: Double] [34,33,33] The package is very simple, yet useful. It's plain Haskell 98. https://hackage.haskell.org/package/apportionment