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Logic Puzzles
“Uncle Bob”

Each month in 2020 I plan to feature a different type of logic puzzle. This month it’s …

Grid and Bear It: KENKEN

Ten years ago New York Times puzzle editor Will Shortz introduced KENKEN, a Sudoku-like puzzle invented by Japanese math instructor Tetsuya Miyamoto, Six free puzzles are posted each day at

As in Sudoku, each row and column will contain a set of numbers without repeats. The 4x4 puzzle will use the numbers 1 through 4, the 5x5 will use 1 through 5, and so on. The grid is divided into sections that specify an operation and a required result. For instance, in the example a 2- specifies a difference of two. Operations are performed either left to right or right to left, top down or bottom up, to insure a positive whole result. Give these a try and then go to NYT and try the daunting 8x8 grid.

Example Problem


Puzzle 1 - use 1 through 4

Puzzle 2 - use 1 through 5

Extra hint for the 6x6 below. Totals of a row or rows sometimes give you some help. Note the cleft separating the first three columns from the rest. Since each column contains 1, 2, 3, 4, 5, and 6 what should the total of those three columns be?

Puzzle 3 - use 1 through 6


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