Lesson notes (textual material) linked to an explicit curriculum
& Worksheets (investigations and activities that include puzzles and games linked
to each lesson)
& Lesson Questions (multiple choice and short answer questions graded at four
levels of difficulty)
& Timed drill and practice questions on basic skills (sometimes called a Basic
Scorcher)
& Lesson Scorchers (like the Basic Scorcher, but with questions focussed on
particular lesson topics)
& Walkthroughs (problems similar to those typically found in school textbooks that
students solve online with step-by-step explanations and feedback)
& Widgets (interactive animations linked to a particular topic).