Simply put

I got the counting thing worked, its not too difficult. So, now this model of the perfect counting machine, you have two things to worry, think pinball. Vacuum plays many flippers. Flipping the little balls as they try to capture them. The flippers are trying to put the balls in baskets of different size, to keep them. They chase it with their baskets. When all the balls have run down hill, you are done.
You can play with a steep bowl, and have big baskets, then the balls run faster, or a flat one, smaller baskets. We prefer the latter game.