Science · Physical Science
Chapter 1: Measurement and the Nature of Science
Extra digits are a claim you cannot back.
In 1868 Carl Wunderlich reported that a healthy person's temperature averages 37 °C, from about a million readings. Converted, 37 °C is 98.6 °F, the number people have quoted ever since.
Is 98.6 °F more precise than 37 °C?
Make your guess to turn the page.
Still to come: 8 pages · Lab · Words to Know · What We Learned · 4 questions · Explain It in Writing · Open Questions
The idea this lesson is working on — Students think more decimal places mean a better answer, because the calculator gives them and a longer number looks careful. The book sets that against 98.6 °F, a conversion that added a digit, and the lab, where one rectangle deserves one, two or three figures depending only on the instrument. Ask: which instrument made the weakest reading, and how many digits did it back? The idea to reach is that every digit is a claim.
Accuracy and precision are different — Accurate means close to the true value; precise means fine and repeatable. A miscalibrated balance gives precise readings that are consistently wrong, and the consistency hides the error. The Mackowiak study (JAMA, 1992) reported 36.8 ± 0.4 °C; Wunderlich’s "about a million readings" is the usual account of his 1868 work, and historians note his thermometers were themselves poorly calibrated.