For ages 8 & up, the four books entitled Plants & Animals, Outer Space & Earth, Body & Health, & Physical Science contain 296 lessons that are broken down into small portions with a color graphic for each. Say the answer & turn the page to check it. Plants & Animals teaches subjects like food chains & webs, plant & mammal groups, pollination, insects, animal habits, & fossils. Outer Space & Earth covers topics such as the solar system, planets & comets, earthquakes, rocks & minerals, & conservation.Learnabout body organs, skin & muscles, blood circulation, & nutrition in Body & Health. Physical Science includes lessons on gravity, compounds, energy & matter, electricity, simple machines, & magnets. This series is ideal for children & adults, parents, tutoring, school curriculum, review, & traveling.