We are in the process of creating Libraries for the Problems of the Week. In addition to a search feature, we will be including a "Special Topics/Themes" area (you could suggest another name for this area).
The idea is that we would design pages which pull together the problems that focus on a particular subject/topic in each of the Problems of the Week. These could be math content (e.g., perimeter) or context (e.g., holidays, gardens).
We'd like these to be as useful as possible for you. So... what are some subjects/topics you'd most like to see as elementary teachers?