Key to Measurement, Book 1, is first in a series of four books on English units of measurement. Book 1 covers English Units of Length and is 45 pages long. The series comes with an answer book containing notes. Key to ...® books are not a complete curriculum but an enhancement to the program of your choice. Key to Measurement was written for students in fourth grade and above. Other books in the Key to Measurement series are Book 2: Measuring Length and Perimeter Using English Units; Book 3: Finding Area and Volume Using English Units; and Book 4: English Units for Weight, Capacity, Temperature, and Time.

Book 1 begins with the history of English units and includes many hands-on activities to help students understand the measuring process. The books in the Key to ...® program speak directly to the student and are intended to be self-paced. I believe that any student would benefit from the Key to Measurement books. The series is well suited to work with all of the math curricula I have used, including Saxon, Singapore, Mequon, and Horizons. I think it is most suitable for grades four to six. While an older student who needed additional instruction in measuring could benefit from the books, I believe he would find it beneath him.

We use Key to ...® books three to five days a week and do one or two pages each day. I like that the program is flexible and does not require me to teach the lesson. My fourth-grade daughter really likes working on Key to ...® books and has learned a lot from the program. The only change I would make is to change to heavyweight paper on the back cover for the cut-out rulers; the lighter paper rulers do not hold up to repeated use. I recommend Key to ...® books to all my friends!

Product review by Tina Rice, Contributing Writer, The Old Schoolhouse® Magazine, LLC, June 2006