This beautiful model to cut out and glue together has twelve sharp spikes emerging from pentagonal cups and forming ten pairs of parallel planes, each in a different colour.
This beautiful model to cut out and glue together is the result of arranging five interpenetrating cubes in a highly symmetrical way. Each cube is printed in its own colour and so it is easy to see that exactly two cubes meet at every vertex and that there are twelve surfaces defining each face of each cube.
Make this collection of seven ingenious paper gadgets which introduce and explain many of the concepts used in cipher machines. Decode the secret messages and then start to understand how cryptographers try to protect information from prying eyes.
This beautiful model to cut out and glue together has sixty spikes, each with three faces, making 180 faces in all. It is coloured in twenty different colours each of which defines a plane surface and which is represented by nine faces. Looked at another way it has twelve clusters of five spikes showing the relationship with the dodecahedron.
Anyone looking for number puzzles to stretch and intrigue will be delighted with the contents of this original book. The demanding challenges explore the properties of numbers and the patterns and hidden relationships which exist between them. Many of the challenges are presented in a visual or diagrammatic way with tables or charts to complete or fill in.
