I struggled with this exercise and didn't understand that it was looking for a summary of goals scored/conceded per team, instead of per match.
My goal here is just to clarify the language, essentially saying "the total number of goals the team scored" to indicate that we are looking for a sum.
Updated the exercise description to clarify this point.
Relates loosely to closed issue https://github.com/rust-lang/rustlings/issues/1361
Evan Miller