The 10 Heavenly Stems and 12 Earthly Branches are the Chinese characters essential in the study of the Four Pillars of Destiny system. The 12 learning sheets are designed to help students to thoroughly master the proper step of writing and pronouncing these 22 characters. These characters are applicable to all Chinese metaphysical subjects including Four Pillars of Destiny, Feng Shui and I Ching Divination.