Chapter 9: “Estimation as Part of Learning to Measure.” In this chapter from NCTM’s Thirty-eighth Yearbook (1976), George W. Bright presents the foundations of estimation, as well as strong sections on preparing to teach estimation and on estimation in the classroom. Please note: This product can only be purchased via NCTM’s Online catalog. Non-web payment methods, such as POs, cannot be used to purchase this item. If you have any questions please call NCTM’s Customer Service Department at 800-235-7566.