Calibron 12 by Creative Crafthouse

Creative Crafthouse

$32.00
Unit price per

Shipping calculated at checkout.

The objective is to make a square and fit them into the large opening of the puzzle. There is only 1 solution and it is very difficult to find.

We packaged the puzzle unsolved, but the solution is provided. In the frame I made an extra space to hold one of the pieces so that we could package it unsolved.

Our version is made from precision cut woods with at least 4 different woods in each puzzle. Ash, Maple, Walnut, Oak, Mahogany, Birch, Cherry, Alder, and other woods may be used with each puzzle have a little unique look. The pieces are very strong at 1/4" thick and have a nice finish. I also laser engraved the relative size of each piece on the piece itself, which may be helpful to you folks who want to attack this analytically. It also makes identifying the pieces easier if you just want to use the instructions to solve it.

Puzzle measures 9" x 7" in the base. The square opening is about 6.3" x 6.3".

One of the many things I like about this puzzle is that it does not look nearly as difficult as it actually is. People seem to get absorbed in it quite readily as you always seem to get close. In fact though, it is a difficult level 5 (of 5) puzzle.

Originally designed in 1933 by Theodore Edison, son of the famous inventor Thomas Edison, and made by his company Calibron Products of West Orange, N.J. It was offered as just pieces and you were told they made a rectangle and there was only 1 solution. Turns out the only possible solution is a square shape, as verified by Ken Irvine's computer analysis. Ken is working on a full analysis of the puzzle, with excerpts noted below. I will link that analysis here when it is available.

From Ken Irvine:

After determining that there was only 1 solution to the square (using Burr Tools program), the second goal was to determine if there were any additional rectangles that could be made with the 12 pieces. The first step of this analysis was to determine how many possible rectangles needed to be checked. Since the total area of the pieces is 3136 units, the problem is to find the set of rectangles that have an area of 3136. This is done by factoring 3136 into its prime factors, which gives: 2 x 2 x 2 x 2 x 2 x 2 x 7 x 7. Rectangles of area 3136 can then be found by finding all combinations of dividing the prime factors into 2 sets. This can be further constrained by the fact that both sides need to be at least 18 units to be able to fit the 21 x 18 piece. This results in the following 4 possible rectangles, including the original square:

(2 x 2 x 2 x 7) x (2 x 2 x 2 x 7) => 56 x 56 (Original Square)

(2 x 2 x 2 x 2 x 7) x (2 x 2 x 7) => 112 x 28

(2 x 2 x 2 x 2 x 2 x 2) x (7 x 7) => 64 x 49

(2 x 2 x 2 x 2 x 2) x (2 x 7 x 7) => 32 x 98 >>

(more to come later on this........)

Level of Difficulty: Level 5

Handmade by Creative Crafthouse in Hudson, Florida.

At Creative Crafthouse, we pride ourselves on offering high-quality, handcrafted wood mind-bender and brainteaser puzzles and games. We know that logic, reasoning, and analytical skills are all vital to cognitive development. The earlier your child or student can hone these skills, the better off he or she will be in life. No matter what your age developing problem solving skills, patience, and determination are important qualities to cultivate.

We know that nearly all people enjoy an interesting challenge and will work at something for hours on end to find the answer. So we do our best to offer interesting, fun, sometimes magical and challenging puzzles with various degrees of difficulty and various types of challenges. Many are our own design and some are historical designs that are unique to us. Most are manufactured right here in our Hudson, Florida shop. We have extensive laser skills along with CNC and traditional woodworking. We are a small family business with 10 employees all striving for top quality and customer service.

Find more work from Creative Crafthouse here.