Biotechnology student teaches mathematics, physics, chemistry and/or Spanish, aimed at students from grade 1 to grade 12. The classes will be based on the following method, which has worked perfectly during my experience: - Practice of exam-type exercises, so that the student is as prepared as possible. - additional didactic activities raised in such a way that they are interesting for their application. - Weekly/monthly exam of what we have practiced so that the subject can be brought up to date.