We are doing science experiments for this unit on simple machines. For example, one of the experiments is making a catapult out of soup cans. If students can bring two – 284 ml soup cans, they can take their catapults home. Any other can that is the same size will work. Bigger cans (398 ml) may not work as well. Check for outdated product as the students will be bringing them home but you might not get your soup back right away! Ptoing!