Make a cube out of straws and have a go at this practical challenge.
Reasoning about the number of matches needed to build squares that share their sides.
How can the same pieces of the tangram make this bowl before and after it was chipped? Use the interactivity to try and work out what is going on!
One face of a regular tetrahedron is painted blue and each of the remaining faces are painted using one of the colours red, green or yellow.