This activity gives students the opportunity to build structures made from chocolate. In the example given, a box-section is compared with a flat plank of chocolate, to see which is the strongest when spanning a gap. The structures are readily related to the context of bridge-building.
Students join flat pieces of chocolate using 'welds' made by melting the chocolate using a bottle of hot water.
The activity is simple and can be used to demonstrate ideas such as the strength of structures, welding, melting, reversible change, strength testing and the properties of materials. It is suitable for primary and secondary school students. The complexity of the task, and the structures built, can be readily tailored for individual groups.