Number Blocks - Pit Khiam Goh by Tom Lensch

When Tom offers me puzzles I always reply with an enthusiastic reply of heck yeah!  All of Pit’s designs quickly become my favourite puzzles, Tom does such nice work that I’m always very impressed!

Jerry wrote a great blog about this cool puzzle:

“Designed by my dear friend and fellow Singaporean Goh Pit Khiam (Goh is the family name), the Number Blocks is a “packing puzzle” that won a Honourable Jury Mention at the IPP35 Nob Yoshigahara Puzzle Design Competition in Ottawa,Canada in 2015.

If you are familiar with Goh’s work, you may have come across several other (physically) similar looking puzzles in the “blocks” family such as his Arrow Blocks, Stumbling Blocks, Road Blocks and Check Box. But don’t be mistaken; while they look alike, each of them are different in their own right in terms of design and solutions and all providing good challenges.

The Number Blocks comprise of Sapele for the box, maple for the pieces and walnut for the digits. Dimensionally it is about 4.5 inches square and 1.5 inches tall. Made by Tom Lensch, the puzzle is of the usual outstanding quality and construction and all the pieces move and slide smoothly.  This is an interlocking “packing puzzle” and the object here is to rearrange the pieces from the start position to the finished position as shown in the photos here. Basically you need to swap the positions of the 3 and the 4 to the right order.

Like most of Goh’s designs, there are not many pieces – just 4 ordinary looking blocks adorned with laser cut digits atop each one. But three of these blocks have extensions popping out from their sides and these protrusions interact with a channel cut into and along all four of the insides of the box. They also restrict each other’s movements within the box. The solution takes a number of steps more akin to a burr puzzle. Difficult? Well, for the more experienced puzzler, not overly so nor frustrating. But this a puzzle which requires you to exercise some thinking and re-evaluate how you would solve a packing puzzle. And typical of Goh’s design style, there is usually a “trick” of sorts to solving the Number Blocks which results in a nice a-ha moment solution.”