Themes: education, technology, innovation, biography, inspiration, changemaker, role model. When his cousin struggled in school, Salman "Sal" Khan decided to help. Since they couldn't get together, Khan tutored her by computer. Soon he posted lessons online for others too. Seeing the need for online learning, he started the Khan Academy. Through the academy, Khan continues his quest to provide a world-class education to anyone who wants one. Blue Delta Books, a Hi-Lo Books biography series, tell the stories of people who have changed our world in profound ways. This series features a diverse group of people. Some are more well-known than others, but all deserve to be highlighted for the positive impact they have had. Each Blue Delta Book features full-color images on every page and tells the person's story from childhood throughout their life. These books are sure to inspire young teen readers. Each book is 48 pages long.