After getting their heart rates up while on a bike ride, a boy named Rico teaches his younger sister Rosa about the heart.
A boy named Lucas has injured his calf muscle in PE class. Lucas and his classmate Mia discuss the body’s muscles.
A boy named Jack who has just broken his leg teaches his younger sister Lissa all the things he learned about bones while at the doctor's office getting his cast.
A girl named Jasmine teaches a younger student at her school everything she has learned about lungs and the respiratory system while researching them for her booth at her school’s Science Fair.
Tim and insists on telling his sister Grace all about the digestive system while their father is sick with a stomachache.
Ava teaches her younger brother Noah that the brain is like a computer, controlling the body through the spinal cord and the nerves.
Exercise! focuses on physical activity while discussing steps children can take to practice healthy lifestyles. Readers are introduced to facts about keeping your heart healthy and muscles strong and how they related to endurance, flexibility, and coordination. Callouts prompt inquiry, further thinking, and close examination of photographs. Additional text features and search tools, including a glossary and an index, help students locate information and learn new words.