GDZ.ru offers a comprehensive list of manuals and workbooks accompanying the main textbook.
: Review of oral and written addition and subtraction techniques.
: Complete the task independently first, then compare your answer with the guide.
: Follow the step-by-step breakdown to see how the problem was solved, especially for word problems.
: Rules for solving expressions with parentheses and multiple actions (multiplication/division first, then addition/subtraction). How to Use GDZ Effectively
Gdzometr archives older versions of the manual for reference.