# Using log tables

1. Sep 8, 2011

how to use a log table..and how to find the value of log 1.6 or log 5.62.
or any other example.

2. Sep 8, 2011

### symbolipoint

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: Sep 8, 2011
3. Sep 9, 2011

### HallsofIvy

Staff Emeritus
Calculators are so common and so easy to use that most texts no longer have log tables or even mention using log tables.