In her efforts to make a comfortable environment, Mrs. Fuddyduddy has been working tirelessly to hang bulletin boards, arrange seats (in a flexible and collaborative way), and create the ambiance that she desires for her best year yet! She has also created quite a mess in her room as she reorganizes all of her materials, furniture and finally gets rid of that giant filing cabinet full of old lessons "gifted" to her from the teacher that left that room 6 years ago. Help Mrs. Fuddyduddy work her way out of this mess by navigating the world of Public Domain resources.
4. Search for the open textbook resource from Rice University. How many 100% free AP textbooks are available for use? ______