Dr. Eureka

You hold three test tubes with coloured balls in them and race to rearrange the balls to match the formula on a card, without ever touching a ball with your fingers. Everything moves by tipping one tube into another. Flip a challenge card, everyone starts pouring at once, and the first player to match the picture and shout "Eureka" keeps the card. Five cards wins. Drop a ball on the table and you are out of that round. The tubes and the pouring are the whole appeal, and children who cannot yet read the rules to anything else can play this one flat out. It is a Kids-shelf favourite in the café, takes fifteen minutes, and adults find it harder than they expect, since the tubes only take two balls before they spill.