If you are teaching German at the A2 level, you have almost certainly come across the Begegnungen series by Schubert Verlag. It is a gold standard for intensive courses.
Good luck with your A2 class—and remember, the answer on page 18 is almost always "Präteritum von 'müssen' ist 'musste'." Begegnungen A2 Lehrerhandbuch Pdf 18
Instead, spend €19.90 on the official e-book. Consider it an investment in your teaching sanity. Having the manual searchable on your tablet means you can jump to page 18, 42, or 101 in two seconds flat. If you are teaching German at the A2