My middle school age son came home from school and said he needed to make a volcano for a project. OK, I thought, that shouldn't be too difficult.
So we headed off for the store to buy modeling clay. On the way, however, he informed me that we would also need vinegar and baking soda. And lots of it. To practice.
"To practice what?" I asked.
"The explosion," he answered.
Of course, I belatedly realized, we couldn't possibly have a volcano without an explosion of lava to accompany it.