In this episode two activities from the mathematics teacher training programme are described. Both of them are based on the so-called “expert-method” in Dutch terminology, or “jigsaw technique” in American educational literature. It relies on dependability between students. It breaks classes into groups and breaks assignments into pieces that the group assembles to complete the (jigsaw) puzzle. The first activity is from a session on the history of calculus and the second is from a session on Euler.