Eye of Horus fractions were written as the sum of two or more unit fractions (a fraction with 1 as the numerator), with scribes possessing tables of answers (see Rhind Mathematical Papyrus 2/n table). Thus instead of , one would write + . Different parts of the Eye of Horus were thought to be used by the ancient Egyptians to represent one divided by the first six powers of two: The Rhind Mathematical Papyrus contains tables of "Horus Eye Fractions". Studies from the 1970s to this day in Egyptian mathematics have clearly shown this theory was fallacious and Jim Ritter definitely showed it
The Horus Heresy (novels) series became a sales success in its category. "Horus Rising" by Dan Abnett, the opening title, set the pace shortly after its release, topping "Locus" magazine's "Locus Bestsellers: Gaming-Related" list of August 2006; practically every title in the series had achieved the same or similar performance on this chart. "Horus Rising"s January 2011 CD audiobook release also appeared in ranked sales lists: the (abridged) edition was number 15 in a related chart published by "The Bookseller", covering 2011 UK sales up to September. "Legion" by Abnett, and "Battle for the Abyss" by Ben Counter, were listed in Nielsen BookScan's list