"With bold black outlines and vivid coloration... the artwork captures the action as the boys exercise their ingenuity."-School Library Journal

The Kang boys don't want their teacher to write embarrassing notes on their hands anymore. Can they concoct a formula for what just may become a very useful school supply?

This series, recounting how the creative Kang brothers discovered four of China's famed inventions, is redesigned to feature new bilingual simplified Chinese translations.