Irregular Killer Sudoku 9x9 5

Irregular Killer Sudoku 9x9 5 Sudoku Killer

You can find sudoku jigsaw puzzles easier or more complicated than normal sudoku. They certainly make fun changes. In addition to the usual sudoku rules, each of the selected areas should total the amount specified for that area.

So in our example (grid 9 by 9), each row and column should contain one and only one digit from 1 to 9. But what makes it a killer are those small numbers in the left corners of each of the red highlighted areas. The digits in a given area must be added to a small number for that area.

This should make your brain think about some interesting new things about numbers!