General help

I would add them all as Resource-Files, probably in a separate topic of their own at the end of your course. Use Stealth mode to hide them but make them available, and then create a list of hyperlinks to the relevant files wherever you need it.

See https://docs.moodle.org/39/en/Stealth_activities

Hi Henry,

I think it would be easier to use the quiz capabilities of Moodle, to generate short, say 10 questions, random quizzes instead of having to maintain 100's of pdf's. That's what I used to do for my students, before I retired. This made it possible for them to practice any time they wanted to, and the grade keeping functions of Moodle let me see each students results. If you use the right question type, one question can give you hundreds of variations of the same question. Based on using the rand_int, in the variable numeric type question it is easy to have just one question that can give thousands of possible questions.

I remember as a kid, having to learn the "times" table by rote from 1 thru 12. Just one question can be used to randomly "test" for any answer among those tables. If you specifically want to do each table, then it only takes 12 questions. You can have the problems shown in horizontal or vertical format.

Note that my students were 7th and 8th graders and generally were pretty weak when it came to questions based on order of operations. Having a bunch of questions of that type really helped them, "see the light" and start getting correct answers. At one time, I even experimented with the PoodLL question type's whiteboard so students would have to "show their work" as to how they got their answer.

by using moodle you can no more need pdf ( except for printing as pdf still the gold)
for simple math
ther is a very powerful question type called calculated multiple choice ,
using it can do few questions that can generate a huge number of question as it randomly generated numbers