Saw the search term “how to score 3 strikes in the tenth frame” land here recently.
I can answer that, but it depends on what happened in the 8th & 9th frames. If you had an open in the 9th, 3 X’s in the tenth is worth 30. The complexity ratchets up from there. If the anonymous searcher trips by again and you still want to know how to score that, leave a comment and I’ll fire you off an example or three.
Or just let the electronic scorers take care of it.