: Sites like Uchi.ru often have tasks aligned with the "Planet of Knowledge" curriculum, though they are categorized by topic rather than specific textbook pages.
If you are searching on Yandex or Google, use these specific terms for better results: matematika 3 klass bashmakov nefedova onlain
ГДЗ Математика 3 класс Башмаков рабочая тетрадь (Solutions for the workbook) : Sites like Uchi