So I have just returned from another great workshop weekend in Barcelona where we welcomed a new group IB mathematical studies teachers to the fold! I get a real buzz from meeting and working with new teachers. One of the many advantages of always preparing and running workshops is that it is very good for stimulating ideas and thoughts. Unplanned, I found myself focussing repeatedly on the idea of 'how much return there is on investment of time in different areas'. Clearly this is a broader question for teaching in general - and that is a whole other post - but in this case, the conversation was about investing teaching hours. The suggestion, I suppose, was that certain topics/approaches may lend themselves to different investments of time. So, with a major disclaimer, here are some of the things I like to invest time in because I think there is a really good return. AND it is important to note that this is probably a very personal thing for different teachers and classes BUT that thinking about where you get your best returns as a teacher is a really worthwhile exercise.