Following Triangles (2014), Adler and Miller tackle another shape.
Again beginning with a definition and descriptions of basic three-dimensional figures and what they are called (sphere, cone, cylinder), Adler quickly ramps up to naming the parts of a circle—radius, diameter, chord, arc. Readers use their own circles, traced onto and cut from paper, and rulers (marked only in English measurements in Miller’s illustrations) to explore these concepts as well as symmetry and intersection. Brightly colored cartoon animals created from geometric shapes (largely circles) ask children to find and count radii, major and minor sectors, and chords. The learning deepens again as Adler looks at ways to find the circumference and area of a circle and the formulas involving pi. The only mathematical calculations readers are asked to do is in determining the area of six different circles using the formula radius x radius x pi = area. A final page looks at the usefulness and ubiquity of circles, though it seems more of an introduction than a conclusion, especially given its simplicity after some math that can be pretty difficult for young learners. Backmatter includes a glossary and the answers to the questions posed in the text.
Another solid shape book that will grow with young geometry learners; don’t let the picture-book format fool you—high schoolers could use some of this math. (Informational picture book. 6-14)