Investigation is a method by which a teacher can teach mathematics at almost any level and also a method by which students can learn by doing mathematics. The typical approach to research at school is as follows: mathematical situation (a problem is presented), experimentation, conjecture, conjecture verification and proof which produces the final result: a theorem (answer). This method makes it possible for students to develop mathematics, rather than merely learning the work of others. The investigative method melds easily with other strategies.