Using Log Tables: Finding Log Values

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  • Thread starter Thread starter Prasad Nemade
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SUMMARY

This discussion focuses on the practical application of log tables for finding logarithmic values, specifically log base 10. It details how to locate log values such as log 1.6 and log 5.62 using a log table, emphasizing the importance of the mantissa and characteristic in calculations. The mantissa for log 5.62 is identified as 0.7497, derived from the log table by cross-referencing the appropriate columns. The discussion also notes the decline in the use of log tables due to the prevalence of calculators.

PREREQUISITES
  • Understanding of logarithmic concepts, specifically common logarithms.
  • Familiarity with reading and interpreting log tables.
  • Basic knowledge of scientific notation and its application in logarithmic calculations.
  • Ability to perform arithmetic operations involving mantissas and characteristics.
NEXT STEPS
  • Study the structure and use of log tables in detail.
  • Learn how to convert numbers into scientific notation for logarithmic calculations.
  • Explore the differences between common logarithms and natural logarithms.
  • Practice using calculators for logarithmic functions to compare with log table results.
USEFUL FOR

Students studying algebra, educators teaching logarithmic concepts, and anyone interested in understanding traditional methods of calculating logarithmic values.

Prasad Nemade
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how to use a log table..and how to find the value of log 1.6 or log 5.62.
or any other example.
 
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Your Algebra book should have a section, either in the chapter section or in the back of the book, for Computations with Common Logarithms, which gives instructions.

For your second example, log base 10 of 5.62, find under the lefthand column of the table, under "x", the value of 5.6. Look over to the right hand side under the column, "2", which in your example is your digit 2 in the hundredths place. You find these cross the value in the table, 0.7497. That was the Mantissa. If you had a number to find log of which was less than 1.0 or greater than 10.0, then you would need to use scientific notation for your given number, and the exponent of your power of 10 would be arithmetically ADDED to the mantissa. That power of ten is called the Characteristic.

log105.62 = 0.7497
 
Last edited:
Calculators are so common and so easy to use that most texts no longer have log tables or even mention using log tables.
 

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