ThinkFun Flipside Review: If you know how to solve Ruben cube, and more importantly, how to find a solution to Ruben cube, this puzzle is much easier. Still it can take about half an hour to come with a complete solution. So it is a fun. The common thing it shares with Ruben cube is that both are about finite permutation groups. Searching for a solution usually starts with repetitative application of a fix permutation, which would equal identity. Then perturb the permutation a bit to get a simple generator of the group.

If you have not touched Ruben cube, this can be served as an introduction to brain teasers based on permutation groups. Forget abstract mathematics in the game. It is still enjoying. But people may lose interest after unsuccessful attemps without “theoretical” guidance.
ThinkFun Flipside Review: I first bought this toy about 3 months ago on Amazon and my family have really enjoyed playing it. This is a great toy if you like some brain challenges. It’s a toy for both adults and kids. Both my wife and I like to play it and even my 4 year old son like to flip the numbers around even though he’s still too little to know how to solve it.

I bought a couple more of this FlipSide toy for our friends’ kids last December and they all love it.

ThinkFun Flipside Description: The flipping, sliding brainteaser challenge. This exciting brainteaser is one of the most unique single-player challenges yet. The object is easy: line up the number tiles from zero to nine. Slide the rows to move the tiles then flip the cylinder to reverse the top and bottom numbers.

The catch is, six of the ten numbers reverse at one time. This flipping, sliding, take-anywhere teaser is not only tough to solve, but it’s tough to put down as well! Slide it, flip it, solve it. It features built-in number tiles and rotating cylinder with ergonomic, easy to grip handles, and a convenient travel and storage box. Ages 8 and up.

Price: $10.39