For this you need some 5 large buckets each with a different substance, (ex. oats, water, flour, etc.). Then get 4 people. ( It doesn’t matter how many people or buckets there are as long as you have one extra bucket.) One at a time, have them come up, pick a bucket, then try to answer any question. If they are wrong, the bucket gets poured on them. If they are right, it doesn’t. Now about the questions: Make it something like playing part of a song then having them sing the next line of it, or have them name it. Questions can be anything as long as its a little challenging.