![Four Colors](https://mail.hootgames.com/wp-content/uploads/2020/05/four-colors-150x150.jpg)
Calcudoku is a really hard and complicated math game. You need to fill all the blocks with numbers. The numbers in a row or column should be different. That’s not enough. The numbers in a frame should be calculated based on the operation from the top left corner. If you want some challenge, play Calcudoku!