Thinking inside the box…

Caramel Box was a big hit at this year’s Nob Yoshigahara Design Competition, taking a Top Ten Votes Award for its designers, Mineyuki Uyematsu and Yasuhiro Hashimoto, while it amused a shed-load of puzzlers. 

I’d had a fiddle around with the competition entry and didn’t get very far at all, so when I spotted a few copies on Mine’s table in the puzzle party, I grabbed one. 

Caramel Box makes a brilliant pocket puzzle – two sets of wooden blocks each need to be placed inside the sheet metal box and the whole she-bang will easily fit in your pocket. 

The box encloses a 3*3*2 space and has an opening across the top (a 2*3 side). The only possible problem to get in your way is a single overhanging square in one of the corners. All you have to do is place each set of three pieces (both of which form a solid a few cubes shy of the required 3*3*2) inside the box so that they aren’t protruding out of the open end… how hard can that be?

Picking a set of blocks to start with (they’re different colours so you don’t unwittingly end up with a set of mismatched blocks) I decided that the best attack would be to find a 3*3*2 assembly outside of the box and then set about trying to work out how to get that assembly into the box – finding an assembly wasn’t too tough, but then exploring how to get it inside the box generated quite a few alternative orientations and rotations… sadly the first several assemblies didn’t turn out to be particularly productive, so I switched strategies and focused instead on getting to an assembly that worked inside the box.

Either I got lucky, or it turns out this is a more productive strategy, as I managed to reduce the number of alternatives I needed to consider quite significantly  and indeed stumble across a solution to the first set of pieces in a matter of minutes (pity I spent more than an hour on the less productive approach!).

Finding the first solution was a very rewarding “A-Ha!” moment – with a number of moves required to successfully manoeuvre all of the pieces into their correct spots to allow the final piece to settle into place. 

Fresh with a victory under my belt, I swapped to the second set of pieces and expected to find a solution in a similar amount of time… only to realise that there’d probably been a fair amount of luck involved in my first solution. 

The solution for the second set of pieces didn’t come as quickly and as a result, I was suitably satisfied when it did finally wander along. Once again, finding an assembly isn’t the real challenge, it’s finding one that allows you to fit it into the box and then reverse-engineering the choreography required to actually get the pieces in there…

This is one of those deceptively simple little puzzles – everything's on show and there are only a couple of pieces to contend with, yet it provides a pretty decent challenge – and the fact that it’ll fit in your pocket makes it dead easy to lug around to torment others with… it’s a great puzzle.

[See what Jerry thought of Caramel Box over here.]