Jacob is a small boy who loves math and surprises! When his grandmother leaves an extra brown bag for him to take to school one day, he is anxious to discover the contents. However, his grandmother informs him that he must wait until he gets on the bus for his school trip to open the bag with his schoolmates. All the kids on the bus are just as excited as Jacob is to discover the contents, and they quickly join in to guess why the contents are so important. Read Jacob's Great Adventure to find out what is in the brown bag and how the contents help Jacob to solve a math problem that day.