Fish

These primers on animal classification focus on essential characteristics of six popular groups. Most pages provide one key trait, such as “all birds have beaks.” One or two high-quality photos provide strong visual support. The fact that “insects have skeletons on the outside,” for example, becomes tangible and more memorable thanks to the image of a rhinoceros beetle that demonstrates it so clearly. A variety of species are used to portray different physical features; this also shows the wide-ranging diversity within each class (less true in Amphibians, which mostly features the frog life cycle). Inaccurate generalizations are avoided with carefully worded sentences like “most [reptiles] lay eggs” and “most fish are cold-blooded.” Principles of classification and further specifics are absent, which is the right choice for the intended age level. VERDICT Smart attention to text and image make this set just right for early elementary students.