This inspiring picture book tells the true story of Katherine Johnson, a brilliant mathematician who loved counting everything as a child. Despite facing racial and gender barriers, she grew up to become a NASA scientist whose precise calculations were crucial for America's first space missions. When Apollo 13 faced a life-threatening emergency in space, it was Katherine's genius with numbers that helped bring the astronauts safely home. The book shows how curiosity, determination, and math skills can solve real-world problems and change history.