Out of the many comprehension workbooks I have used and reviewed, this series is my personal favorite. It contains great variety in subject matter and excellent thinking questions. Before reading each of the 31 reading selections per book, a short introduction gives a little background information and states the reading skill to be emphasized. Selections include pieces on general topics, mathematics, philosophy, literature, science, social studies, logic and thinking, language, and the arts. Because this is a secular program, you may choose to preview some of the reading selections, particularly in the upper grades. Following the selections are questions which require students to find the main idea, identify sequence, draw conclusions, make assumptions, match vocabulary words to meanings, and identify and interpret facts. Although this series is my favorite, our children are not as certain, since these books really made them think. Please note that there are no answers included in the workbooks. All answers are provided in the small Teacher Keys, available for each workbook as a separate but inexpensive purchase.