Each animal is given a random number at the beginning of each round. The goal is to order the animals from the lowest on the left to the highest on the right. You cannot tell what the animals' numbers are, but you can compare: If you click on an animal, and no other animal is selected, the animal's nose will move slightly upward/the animal will rotate a little bit. This means it is selected. Only one animal can be selected at a time. If you click another animal, the original animal will stay selected if its number is lower, and the new animal will instead be selected if ITS number is lower. You can deselect an animal by clicking the balloon. If an animal is selected, and you think it is in the right place, click it again, and you can "mark" it as being in the right place, so that you can focus on the other animals. This means the animal will flip upside-down. If you want to unmark it, click it again, and it will turn right-side up and be unselected. Animals can only move to an empty space, which is just above the upside-down apple. The spaces are right above the apples. Since there are 9 apples and 8 animals, there is only one empty space at a time. To move an animal to the empty space, click the apple below it.