I think I've got it updated using @kazk's idea. I've also scaled it up or down by multiples of 10 randomly.

Thanks, that's a good idea. I saw that you'd done that and was wondering why.

I think there's something wrong with the Kata Editor. Every time I run "validate solution", the top of the output window shows something like Time: 379ms Passed: 0 Failed: 0 Errors: 1 and there's nothing in the output console (even when nothing has changed from when I published it yesterday). So, for the moment I haven't been able to update using assertDeepEquals yet.

Also, when the editor is working again, I'll update the random tests to have a Benford-ish distribution.

Thanks for the suggestion, I didn't see Test.assertDeepEquals in the test framework docs. I'll try to use that instead.