I announced this in class, but for the record: if you choose to do the extra credit (Trees are easy to draw) and turn it in to me sometime prior to the final, it can count for up to two homework scores.
Here’s how that works: If you basically ace that extra credit assignment, that’s two √++es in place of your second- and third-lowest homework scores. Partial credit is possible, so even if it doesn’t raise your lowest homework scores all the way to that level, it will improve them.
But the limit on extra credit for homeworks is nevertheless two homeworks’ worth. This means that if you also turned in BUCLD talk summaries, the potential available extra credit for the new extra credit assignment is less, but then again, it’s also easier to reach √++es on both of them. If you happen to already have √++es on everything, then the extra credit won’t actually result in anything extra (but it will still have a certain character-building value, I suppose).
This is kind of complicated, sorry, but I want it to be relatively fair. So, in summary, you will have 11 homework scores total by the end of the semester. The lowest one will be forgotten. The next two lowest ones are vulnerable to being improved/replaced by turning in the extra credit assignment(s). Your highest 8 scores are whatever they are. Maybe it’s not that complicated after all.