Timekeeping

June 1, 2013

Gr 5-8-This title digs into the concept of timekeeping and shows not only the complexity, but also the malleable system that is just another creation of humankind. Readers will understand the reasons behind the International Date Line, prime meridian, daylight savings time, and other timekeeping systems. Written in a conversational tone with cartoon illustrations and clock-shaped "Did You Know?" fact boxes, it is an approachable and fascinating read that includes 15 projects ranging from simple to complex that, for the most part, can be completed with household materials. Kids can use a penny and a quarter to illustrate the difference between a solar and sidereal day, they can build a sandglass with a couple of plastic bottles, or discover how GPS works with three friends, a field, and a quarter. There are activities that will yield a number of amazing facts, such as the 300 different time zones that existed in the U.S. in the 1800s, and mind-blowing concepts, such as J. William Cupp's metric time system. Make time for this title.-Heather Acerro, Rochester Public Library, MN

Copyright 2013 School Library Journal, LLC Used with permission.

December 1, 2012
Grades 4-7 This latest installment of the Build It Yourself series deals with the highly commonplace but extremely abstract concept of time and timekeeping. It begins with a brief introduction of the birth of time, discussing why and how prehistoric people conceived of ways to measure minutes, hours, and months. Milestones in the development of navigational and timekeeping instruments are highlighted, and biographies of several notable inventors are outlined. The text is heavy on jargon, but a glossary defines unfamiliar terms and Words to Know are highlighted in the margins. Fifteen versatile and hands-on projects range from very simple exercises that can be completed in moments, such as reading seasons from a shadow, to more sophisticated temporal experiments like making your own incense clock. These projects could be used as a fun diversion on a rainy afternoon at home or as the crux of an elementary science lesson.(Reprinted with permission of Booklist, copyright 2012, American Library Association.)