How to find mantissa in log table

Step 1

Choose two numbers that can't be easily divided using pencil and paper. For example, 82,310 can't be easily divided by 162.

Step 2

Express the numbers in terms of base 10 logarithms.

The number 82,310 can be expressed as log82310 (the base of 10 is understood) and 162 can be expressed as log162.

Step 3

Use a logarithm table to determine the logarithms of both expressions. For example, log82310 is 4.9153998.

To do this, look up log8.231 to get the numbers to the right of the decimal point, then add a 4 to the left of the decimal.

How to solve bar in maths

Log162 is 2.2095150

Step 4

Subtract 2.21 from 4.915 to get 2.7058637.

Step 5

Use the logarithm table to find the antilog of 2.7058637. To do this, look up .7058637, then move the decimal place of the result to the right two places.

The answer is 508.