Calcudoku: Solving an easy 6x6 and a difficult 4x4

Solving these step by step to hopefully give people some insight into possible solving methods.
Do suggest which other types of puzzles should be solved in a video :-)
The intro music is a small part of "X Ray Vision" by Slynk, from the Youtube audio library.

Видео Calcudoku: Solving an easy 6x6 and a difficult 4x4 канала calcudoku