00639naa#a2200169#i#450# EN\INFRA-M\bibl\115162 20260312141551.4 1998-0728 20260217b2026####ek#y0engy0150####ca RU Improving the Quality of Mathematics Education for Primary School Students: Methodological Recommendations for Studying Difficult Topics Journal article Moscow INFRA-M Academic Publishing LLC. 2026 6 с. Journal article local Организация обучения в начальной школе. 373.31 Smoleusova T. V. zh-szf.ru