The world begins by asking you to type the perimeter of the square, given the length of one side in centimeters.
If you get it right, the caterpillar inches around the edges. If you get it wrong, you can click the question mark for help and try again.
You are asked for the area of the square, and the caterpillar crosses to the other corner.
Once you have completed the two square questions, the caterpillar turns into a butterfly and flies to the rectangle. You get to answer the same questions for the rectangle and then for a circle.