Most Russian schools follow specific textbooks. You can find ready-made solutions (GDZ) for these directly on platforms like Skysmart Solutions or Allmath.ru :
: While not a traditional "reshebnik," this platform offers interactive games and problem sets that align with early school levels. 📚 Popular 2nd-Grade Math Solution Guides (GDZ) reshebnik po matematike dlia 2 klassa skachat programma
If you need a digital "program" to solve problems on the go, these apps are highly effective: Most Russian schools follow specific textbooks