Mike loves riding his bicycle. This year he wants to ride in the annual 15-kilometer race around Perimeter Park, just like Justin and Marissa and all the other big kids. His practice ride around the athletic field was only 6 km, while the ride around the zoo was just 9 km. It's going to be a tough race. Good thing Bingo the dog is there to cheer him on. Perimeter—the distance around a shape—is an important measurement concept for children to understand. Used with permission from Stuart J. Murphy.