Thomas Snyder (aka Dr. Sudoku) is a two-time World Sudoku Champion and five-time US Puzzle Champion, as well as the author of several books of puzzles. His puzzles are hand-crafted, with artistic themes, serving as a kind of “cure for the common sudoku.” Each week he posts a new puzzle on his blog, The Art of Puzzles. This week’s prescription is a calcudoku variation where there’s something missing in each row and column.
While this week’s puzzle may look normal from the outside, there’s something missing on the inside. Where you might expect to see six numbers, you will only need to fill in five, leaving one spot in each row and column blank. A blank cell will have no effect on the indicated operation and can be treated like the identity element (0 for addition, 1 for multiplication). The rules are otherwise unchanged.
Example (with 1-3):
Rules: Place a digit from 1 to 5 (or no digit at all) into each cell so that each digit appears exactly once in each row and column. The values in the upper-left of the bold cages indicate the value of an operation applied to all the digits entered into that cage. Numbers can repeat within a cage. Blank cells do not influence the values of the operations.