Ages 9 to 12 years. A trip to the park for Engineering Kids Pedro and Violet turns into a learning adventure when they come upon a construction site. Violet teaches Pedro about concrete and how engineers use it. Pedro also learns about an engineer's responsibility to design buildings and bridges that are strong and safe for people to use. This book is the first in a unique series of books for children ages five to nine and is the only series written by professional engineers specifically designed to incite an early understanding of and interest in the different fields of engineering. Future books will introduce children to other engineering fields such as geotechnical and electrical engineering.