"GDZ po didakticheskomu materialu" refers to answer keys for Russian didactic workbooks, often covering 6th-grade mathematics (Chesnokov, Neshkov) or 8th-grade algebra (Makarichev, Mindyuk). In a broader educational context, didactic materials are self-correcting, concrete tools designed for skill-specific learning. Detailed answers for specific school materials can be found at resources like Gdz.ru gdz.ru or Resheba resheba.me. A Glossary of Montessori Terms