Circles

Frequent collaborators Adler and Miller follow their books on fractions, time zones, triangles, and other topics with a thorough look at all things circular. After a brief run-down of two- and three-dimensional shapes with round aspects (cylinders, cones, spirals, etc.), Adler dives into what makes a circle a circle, unloading a significant amount of vocabulary along the way, including words like symmetrical, diameter, sector, and chord, all clearly explained in direct writing, assisted by hands-on project ideas and Miller's playful circle-based animal portraits. By the time children get to the closing line--"We live in a world of circles"--they'll be convinced. Ages 6-10. (Aug.)

Gr 2-4--In this companion volume to his equally attractive and useful Triangles, Adler addresses the geometric world of circles. Starting with an introduction to the realm of noncircles (spheres, cylinders, cones, etc.), he then launches into circular spaces--complete with centers, points, diameters, radii, chords, and other potentially unfamiliar terminologies. Simple, logical activities are presented to drive concepts home, including popping into the world of pi and challenging young geometers to find the areas of a gaggle of bright circles. Miller's bright illustrations provide an excellent guide for the experimental activities. A glossary is appended, as are solutions to the challenges in the text. Math teachers and homeschooling parents will be delighted with this clear, concise overview of a familiar shape with unexpected details. VERDICT Extremely useful for the classroom at home or in school, and very approachable in its colorful minimalism.--Patricia Manning, formerly at Eastchester Public Library, NY