We see different examples of the materials used to make bridges, including stone, cast iron, brick and steel. Using plastic is a good idea; it is light, easy to build from, doesn't need cranes, and can be glued together. To give it strength, plastic can be reinforced with glass. This makes it strong and flexible enough to support its weight two times over.

First broadcast:
24 September 2007

This clip could provide a stimulus for discussions on identifying a range of everyday materials, comparing how they are used in the world around them and suggesting reasons why a material would be suitable or not, for a particular purpose. Children could go on a material hunt around the classroom or school, identifying a range of everyday materials that they can find. Alternatively children could sit in a circle and suggest why a material would not be suitable for a particular purpose. For example: “A teapot cannot be made from chocolate because it would melt”” or “A window cannot be made from wood because it is opaque.”