Cube Nets
Of all the shapes made from six joined squares, exactly 11 fold into a cube, if turned or flipped copies count as the same. Place squares to build a shape, press Fold to see whether it really closes into a cube, and fill in the collection.
Tap the 5×4 board to build a shape of six squares.
How to play
Tap squares on the 5×4 board to build a shape of six squares (tap again to remove one). Once the six are joined, press Fold and the solid on the right folds up one square at a time. If the six faces fit exactly, the shape is a cube net. If two squares land on the same face, or a face is left empty, it does not fold into a cube. Shapes that match after turning or flipping count as one, and each one you find goes into the collection below. Tap a shape in the collection to put it back on the board.
Learn more
Six squares joined edge to edge make 35 different shapes if turned and flipped copies are counted once, and exactly 11 of them fold into a cube. The tests fold all 35 for real, by two independent methods (rolling a cube across the shape, and folding it in 3D coordinates), and the answers agree. The 11 are six “1-4-1” shapes (a row of four with one square above and one below), three “2-3-1” shapes, and one each of the staircase “2-2-2” and “3-3” shapes. No shape that contains a 2×2 square can fold into a cube.