Francisco el Matemático, also known as Francisco el Matemático: Clase 2004 for the sixth season, is a Colombian teen drama television series produced and broadcast by RCN Televisión between May 1999 to October 2004. The series revolves around Francisco, a young math teacher who must deal with the personal problems of his high school students. The series is considered one of the most watched productions of Colombian television, together with Padres e hijos. After its resounding success, in 2004, Pedro Damián of Televisa produces a Mexican version of the series with the title of Clase 406.On 10 November 2016, it was confirmed that the series had been revived in a new sequel. Which consists of 73 episodes and premiered on 13 February 2017, and concluded on 2 June 2017. Due to the low ratings that the sequel had, it was canceled after 73 episodes aired.The main character of Francisco el Matemático, was played by 4 actors, initially starting with Luis Mesa as Francisco Restrepo, who was in the series from 1999 to 2000. Following him, Ricardo Vélez assumed the leading role as Juan Francisco Reyes during the years 2001 and 2003. In 2004, due to the low rating of the series, it was canceled, but during that year the title was changed to Francisco el matemático: Clase 2004, and the main character was played by Alejandro Martínez as Francisco Santamaría. 13 years later after the series' cancellation, Carlos Torres resumed the character as Francisco Quintana in a new sequel.