00511naa#a2200169#i#450# EN\\bibl\99194 20251208105355.1 2542-1840 20250527b2025####ek#y0engy0150####ca RU Design and Research Activities in Mathematics Education Journal article Kemerovo Kemerovo State University 2025 9 с. Journal article local Evstifeeva Tat'yana Valentinovna Stacenko Anastasiya Igorevna jsocnet.ru