Elementary

Sometimes prices go up and up and up. Then they suddenly crash. Why? In simple language and with colorful graphics and amusing characters, this picture book explains the basic laws of supply and demand, using examples kids will understand, such as dueling lemonade stands on the same block. Terms such as "fixed costs" and "variable costs" are clearly explained, and a glossary as well as a helpful graphic summary are included.

When a terrible famine struck William Kamkwamba's tiny village in Malawi, his family lost all of the season's crops, leaving them with nothing to eat or sell. The family could hardly find money for food, let alone school fees. forced to drop out of high school, William began to explore the science books in his village library. There, he came up with an idea that would change his family's life forever: He could build a windmill.

Christopher Ludwick is a German-born American patriot with a big heart and a talent for baking the best gingerbread in Philadelphia. No one goes hungry if he can help it--"Not in my America!" he says. When cries of "Revolution!" begin, Christopher marches off to feed General George Washington and his hungry troops. But Washington never expects his favorite baker to sneak off on a risky secret mission across enemy lines...