This is the summary of a presentation given at the Joint Mathematics Meetings, January 10-13, 1996, Orlando, Florida.

What mathematics do teachers need to know, why do they need to know it, and how can we help them learn it? This talk touches on (provisional) answers to these questions, on ways to arrive at answers, and on the interplay between working with teachers and teaching college students.

Judith Roitman, University of Kansas