Much of math history comes to us from early astrologers who needed to be able to describe and record what they saw in the night sky. Whether you were the king's court astrologer or a farmer marking the best time for planting, timekeeping and numbers really mattered. Mistake a numerical pattern of petals and you could be poisoned. Lose the rhythm of a sacred dance or the meter of a ritually told story and the intricately woven threads that hold life together were spoiled. Ignore the celestial clock of equinoxes and solstices, and you'd risk being caught short of food for the winter. Shesso's friendly tone and clear grasp of the information make the math ''go down easy'' in this marvelous book.