Welcome to Bob’s Numerichain Puzzle Page

Numerichains are puzzles of logical and numerical deduction. The goal is to determinine the location of every number in a grid of squares. The numbers form a “chain”. 1 will be next to 2, 2 will be next to 3, and so on (diagonals don’t count).

In the example at right there are ten rows and ten columns, so the chain uses the numbers 1 through 100. In the puzzle you are not shown the numbers in each box;— that’s what you are trying to figure out. Instead, you are shown the blue areas and are told which numbers are in them. The tricky part is that you aren’t told the order of those numbers. For example, you’re told that the blue area near the left of the middle row contains 43, 93, 98, and 99, but it’s up to you to figure out which goes where.

You can get more information by making additional queries (more blue areas). But the goal is to solve the puzzle with as few queries as you can. Believe it or not, the eight queries in the puzzle shown are enough to solve it. No other number chain can fit the information given.

How To Solve a Numerichain Puzzle

5 by 5 puzzles Jul/31/2003
7 by 7 puzzles Jul/31/2003
9 by 9 puzzles Jul/31/2003
9 by 11 puzzles Jul/31/2003
9 by 11 puzzles (no queries at start) Aug/1/2003
10 by 10 puzzles Jul/31/2003
7 by 15 puzzles Aug/1/2003
14 by 14 puzzles Aug/1/2003
19 by 21 puzzles Aug/1/2003
20 by 20 puzzles Aug/1/2003

Reindeer In A Blizzard (2003 Christmas Card Puzzle) Dec/2/2003