Mathepillar is an outrageously fun game in which players have to order falling numbers on a number line by positioning their caterpillar in the correct place to catch the numbers. There are four stages to the game, and each stage presents a slightly more complicated number line or pattern. If a player can pass all four stages, he or she can print out one of six limited edition butterfly certificates, each featuring a different species of butterfly. Try to collect all six!