In the study of ancient Egyptian mathematics, red auxiliary numbers are numbers written in red ink in the Rhind Mathematical Papyrus, apparently used as aids for arithmetic computations involving fractions. It is considered to be the first examples of method that uses Least common multiples.
References Gillings, Richard J. (1982). Mathematics in the Time of the Pharaohs. Dover Publications. ISBN 9780486243153. OCLC 301431218. Clagett, Marshall (1989). Ancient Egyptian Science: Ancient Egyptian mathematics. American Philosophical Society. ISBN 9780871692320. OCLC 313400062. Bunt, Lucas N. H.; Jones, Phillip S.; Bedient, Jack D. (2012). The Historical Roots of Elementary Mathematics. Dover Publications. ISBN 9780486139685. OCLC 868272907.