History   Help on query formulation   Computing logarithms by hand. (English)
Math. Teach. (Reston) 109, No. 8, 633-636 (2016).
Summary: How can old-fashioned tables of logarithms be computed without technology? Today, of course, no practicing mathematician, scientist, or engineer would actually use logarithms to carry out a calculation, let alone worry about deriving them from scratch. But high school students may be curious about the process. This article develops a straightforward technique for computing common logarithms by establishing a few successive square roots of 10. Because the logarithms of these values are by definition just the power to which 10 has been taken (\$1/2\$, \$1/4\$, \$1/8\$, etc.), these values can be used to construct a table of logarithms in which the increment in the logarithm is \$1/2^N\$, where \$N\$ is the number of square roots computed. By interpolating between these accurately computed points, we can build a standard log table. This method should help reinforce rules of logarithms and powers for students. (ERIC)
Classification: F50 N50