Score
0
Best
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A flat net of six marked squares, four cubes. Only one of them is the net folded up — spot it before the clock runs out.
At the top of the screen is a net: six squares joined edge to edge that fold up into a cube. Each square has its own colour and its own shape, and the shape is printed in one corner of the square rather than in the middle. Below the net are four cubes, each seen from one corner so that three of its faces are showing. Exactly one of the four is the net folded up with the printed side outward. Tap it.
The shape tells you which face you are looking at, and the corner it sits in tells you which way that face has been turned. That second part is what makes the puzzle. A cube can show the right three faces and still be wrong, either because one of those faces has been turned a quarter or half way, or because the whole corner is the mirror image of the real one, with the same three faces running round the corner in the opposite direction.
You have ninety seconds. Every right answer is worth a point. A wrong answer costs a point, and the buttons lock for a moment while the correct cube is outlined in green so you can see where you went wrong. The wrong answers begin as easy ones, where two faces that end up opposite each other are shown side by side, and become subtler as your score rises, moving on to turned faces and finally to mirror images.
Every puzzle is checked before you see it. The folded cube is turned through all twenty four orientations it can take, and the right answer is chosen from that list while each wrong answer is confirmed to be missing from it. There is never a trick question and never two right answers.
Start by ruling out the impossible, not by folding. In any net, squares that sit two apart in a straight line end up on opposite faces, so they can never be seen together on one corner. Find those pairs first, and any cube that shows both members of a pair can be discarded without any mental folding at all. On the early questions that alone finds the answer.
When three faces are all allowed, fold only one edge in your head, not the whole cube. Pick two squares that touch in the net and notice which of their corners meet along the shared edge. Those two corners stay together forever, however the cube is turned. If the marks on those two faces sit on the shared edge in the net, they must sit on the shared edge of the cube as well, right next to each other.
Mirror images are the hardest wrong answers because every face and every mark looks right. Check the direction instead. On the net, pick three squares that meet at one point and read them clockwise. On the correct cube the same three faces read clockwise around the corner nearest to you in the same order. A mirror image reads them anticlockwise, and that is the only thing that gives it away.
Speed comes from reusing what you have already worked out. The four options share the same net, so once you know which faces are opposite and which way two of them meet, that knowledge applies to all four cubes at once. Check the cheapest thing first on every option, and only reach for the clockwise test on the ones that survive.