Pete and Carla are students. One day they look at some very old coins and stamps in a shop. Pete wants to buy some stamps, but they are very expensive. Later th

Original / British English Pete and Carla are students. One day they look at some very old coins and stamps in a shop. Pete wants to buy some stamps, but they a

Second graders Ethan and Ella are sad about moving away from their hometown to travel the world with their mom, a journalist, and dad, who will home school them

When ten-year-old Derek and eight-year-old Sam move with their family to Virginia, they have no idea what adventures the summer will bring. As the brothers expl

Developed from celebrated Harvard statistics lectures, Introduction to Probability provides essential language and tools for understanding statistics, randomnes