The World of Tan section began in October 1999 and each month provides a discrete episode in the story of Grandma T, her family and their removal business. The characters are always getting into bother, solving problems and having little adventures - always, of course, related to some mathematical topic. The focus activity is to solve the tangram puzzle. An outline of a figure is given and the puzzle is to work out how to fit the seven tangram pieces together to make it. It is therefore essential to have a tangram set.
Plastic sets are readily available from toy stores and educational suppliers.
Or you could fold your own from a square of paper. While solving the puzzles, children engage in spatial thinking and develop key skills such as visualisation, mostly without realising it. Below is a list of some of the concepts and skills involved. Many children have difficulty in visualising what a shape would look like when turned or flipped. This is a website, apparently based in the USA, which was started by a group of parents as a service to other parents, with the main purpose of providing information on the health, education and the general development of children.