Arithmetic operators in haskell appear to require their operands to have the same type. How can I do arithmetic between operands of different types? Alternatively, how do I coerce a value from being an Int to being a Double? I am new to haskell. I have read a few tutorials but they do not mention this issue. I have read the haddock documentation for Prelude and Numeric, but cannot find anything that helps here. (I saw a couple of numeric conversion functions, but they won't turn an Int into a Double.) Toy example: $ cat eg.hs calc :: Int -> Double -> Double calc count weight = count * weight $ ghc eg.hs eg.hs:2: Couldn't match `Int' against `Double' Expected type: Int Inferred type: Double In the second argument of `(*)', namely `weight' In the definition of `calc': calc count weight = count * weight