By Jan Kok
There are a zillion ways to add numbers mechanically, display the result, and constrain the result to a desired range.
The voters can each select one of 11 (for 0-10 Range-Voting) punches or markers to unambiguously punch or mark the addend ballots.
Note that it's a long way from "here" (these discussions and papers) to "there" (implementation in real life, when we can revisit the question of which range to use).