8th-graders have been working on learning how casting works and how they could make replicas of everyday items. We ran into an interesting technique that uses 100% silicone caulk and cornstarch; this mixture allows for a quick casting of items and can also make some really interesting bouncy balls. It can lead to a huge mess with cornstarch and strands of silicone all over the tables but that is a fine price to pay for the fun of exploration.