The most popular image associated with kata is that of a karate practitioner performing a series of punches and kicks in the air. The kata are executed as a specified series of approximately 20 to 70 moves, generally with stepping and turning, while attempting to maintain perfect form. There are perhaps 100 kata across the various forms of karate, each with many minor variations. The number of moves in a kata may be referred to in the name of the kata, eg. Gojushiho, which means "54 steps." The number of moves may also have links with Buddhist spirituality. The number 108 is significant in Buddhism, and kata with 54, 36, or 27 moves (divisors of 108) are common. The practitioner is generally counselled to visualize the enemy attacks, and his or her responses, as actually occurring, and karateka are often told to "read" a kata, to explain the imagined events. In teaching the open handed kata, most styles of Karate start with a series of three, or sometimes two, very simple kata called blocking forms before advancing to five basic kata named Pinan in some systems and Heian in others. By working through this series (in order: Shodan, Nidan, Sandan, Yondan, Godan (except in Wado Ryu Karate, where Shodan and Nidan are reversed)) the practitioner learns all the basic stances and techniques before moving on to more advanced kata. Traditionally, kata are taught in stages. Previously learned kata are returned to in order to show more advanced techniques or ways of doing things, as beginners do not have the same knowledge and experience that practitioners further up the ranks have. It is not uncommon in some styles for students testing for Shodan (first rank black belt) to have to repeat every kata they have learned from the first belt, but at a "black belt" level, for example, with better technique, power, amongst others. This system is often used for the lower grades as well. The student will perform one new kata and one or two previous ones, to demonstrate how much they have progressed and how quickly they can learn new things.