sum_list = [5, "four", "two", 10, "one", 28, 6, "five"] defmodule SumModule do @words_with_index Enum.with_index(["one", "two", "three", "four", "five"], 1) @words_to_numbers Enum.into(%{}, @words_with_index) def sum_list(list) do list |> Enum.map(&to_integer/1) |> Enum.sum() end defp to_integer(number) when is_integer(number), do: number defp to_integer(other), do: Map.get(@words_to_numbers, other, 0) end IO.puts SumModule.sum_list(sum_list)