Juan de Ortega

Juan de Ortega (born Palencia, Spain, c. 1480; died c. 1568), was a Spanish mathematician. He wrote some of the earliest works on commercial arithmetic, and discovered an improved method for calculating square roots.

Life Very little is known of Ortega's life. He was a member of the Dominican Order in Aragon, publication among Ortega's works was Tratado subtilissimo de Aritmetica y de Geometria ("Most refined treatise on arithmetic and geometry") (Barcelona, 1512). The work was published in Spain, France and Italy, and translated into several languages. this work also introduces a novel approximation method for calculating square roots, which appears to be largely based on the Pell equation and thereby the best available technique, even though no general solution of this equation is known to have been found until much later.