 
Summary: Math Is Not a Spectator Sport
Helmer Aslaksen
Department of Mathematics
National University of Singapore
Singapore 117543
Singapore
aslaksen@math.nus.edu.sg
www.math.nus.edu.sg/aslaksen/
When I first started out as a teaching assistant I was very conscientious. I spent
a lot of time talking to my students outside of class, trying to find out what they
didn't understand and finding ways of explaining it to them. I would then proceed
to give minilectures during my discussion sessions, trying to cater to both the
weaker and the stronger students. I was quite pleased with the way I conducted
my classes, and I got a lot of positive feedback from my students. There was just
one slight problem: Every so often students would lose their concentration and
my beautiful presentation would be useless.
This gradually made me realize that one of the basic problems in teaching is
simply to keep the students focused on what is happening, or to put it more bluntly
 keep the students awake! I tried several methods, ranging from telling jokes
to periodically slamming the blackboard with the eraser. They were all somewhat
