Robertson 
Circles and Rectangles [PDF ebook] 

In Circles and Rectangles, readers will learn how shapes show up in their everyday lives. This 24-page title features colorful visual aids, simple text, comprehension and extension activities, and more to effectively engage beginning readers and reinforce the basics of early shapes. The Concepts: Shapes and Numbers series takes the learning of basic concepts to the next level. By connecting colors, counting, and shapes to what children know will result in greater understanding. Colors looks at the colors found in different seasons, Counting introduces children to the different ways they can count their favorite things, and shapes allows them to be creative and see what they can build.