Attached is an MWE of a weird quirk in answer scoring. There are three questions: the answers are
But WW accepts things like 0.00001, 0.000001, etc. for answers 2 and 3. This would make sense if the tolerance were absolute, but it shouldn't be: the default for Reals is supposed to be relative, yes?
Even weirder: removing the multipart scaffolding makes the behavior change: it then seems to revert to relative tolerance.
I suspect part of the issue is the line
$answer_evaluator_1 = (num_cmp($ans, mode=>'strict', tol=>0.5));
I don't understand what the "" is doing at the end - this is legacy code written decades ago.
I think this may be a very obscure bug.