After a cursory search of the library browser, it seems the next step should be a cursory search of these forums. Entering "long division" in the "Search forums" input above gives https://webwork.maa.org/moodle/mod/forum/search.php?id=3&search=long+division. Scroll down on the first page and you will see some posts that are exactly about this.
As to answer rule sizing, if you are using MathQuill the inputs are rather small and work quite well for a single digit but grow dynamically to accommodate more. If you are using text inputs, then use a small size argument for the ans_rule method. Something like 1 works well for a single digit. You could also use css to do a little better.
As to answer rule sizing, if you are using MathQuill the inputs are rather small and work quite well for a single digit but grow dynamically to accommodate more. If you are using text inputs, then use a small size argument for the ans_rule method. Something like 1 works well for a single digit. You could also use css to do a little better.