Mathematics made mouth-watering.      Things to Make and Do in the Fourth Dimension is an alternative math class. How can math help you choose a second-hand car? Why is a text message like a Sudoku? How much fun can you have with a barcode? Matt Parker explains that math is difficult because it's one of the few subjects that requires us to train our brains to think in an entirely new way, and to confront things with no direct analogy in everyday life--imaginary numbers, snowflakes that only exist in 196884 dimensions, and objects beyond infinity--and shows us why it's worth the effort.     Starting with basic arithmetic and geometry, Things To Make and Do teaches us the math we never got to enjoy at school. Each chapter is structured around activities and thought experiments: we are invited to make a calculator out of dominoes, find out why wrapping oranges in plastic wrap is a good way to learn about higher dimensions, and discover what soap bubbles have to teach us about calculus. A series of incremental and hugely entertaining steps take us all the way from simple algebra to the most exotic and fascinating ideas in mathematics: Klein bottles, higher dimensional topology and the many different species of infinity, via unimaginably small pizza slices, Mobius strips and a thorough examination of The Sausage Conjecture.     This lively, funny, and deeply intelligent book teaches math in a fun, interactive manner rather than by rote learning and exercises. You'll not look at the number 37 the same way again. And you just might take part in Mobius strip craftwork. - from Amzon