Using Log Tables: Finding Log Values

  • Thread starter Prasad Nemade
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In summary, to use a log table, find the value of the given number in the left column and then find the corresponding value in the right column. For log base 10 calculations, the right column represents the mantissa and for numbers less than 1 or greater than 10, the characteristic is added to the mantissa. Most textbooks no longer mention log tables due to the widespread use of calculators.
  • #1
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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  • #2
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
 
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  • #3
Calculators are so common and so easy to use that most texts no longer have log tables or even mention using log tables.
 

1. What are log tables used for?

Log tables are used to simplify the process of finding logarithmic values. They allow users to quickly and accurately find the logarithm of a given number without having to perform complex calculations.

2. How do you use log tables?

To use log tables, you first need to determine the number of digits in the given number. Then, locate the corresponding starting digit in the log table and read off the logarithm value. Finally, adjust for any remaining digits in the number to get the final logarithm value.

3. Can log tables be used for all numbers?

No, log tables are typically only available for numbers between 1 and 10. However, with some adjustments, they can also be used for larger numbers.

4. How accurate are log tables?

Log tables are generally accurate to four or five decimal places. However, the accuracy may vary depending on the quality of the table and the interpolation method used.

5. Are log tables still relevant in modern times?

While log tables were widely used in the past, they have become less relevant with the advent of calculators and computers. However, they still serve as a useful tool for understanding logarithms and can be helpful in certain situations where calculators are not available.

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