Assuming you have a calculation function like:
calculate :: Int -> Int -> Int
you can do
calculateAll :: [(Int, Int)] -> [(Int, Int, Int)]
calculateAll = map (\(x, y) -> (x, y, calculate x y))
or more generally:
calculateAllWith :: (a -> b -> c) -> [(a, b)] -> [(a, b, c)]
calculateAllWith f = map (\(x, y) -> (x, y, f x y))