Curated OER
December Math
In this December math activity, learners click on the links to help them answer math problems dealing with issues in December such as electricity, tree shapes, and money. Students complete 7 problems total.
PBS
Pbs Learning Media: Shape of Trees: The Frustration Principle
This series of images shows the work of biologist Karl Niklas on the adaptations and evolution of plants. From The Evolutionary Biology of Plants.