- Logarithms to the base 10 are known as common logarithms.
- The logarithm of a number contains two parts, namely ‘characteristic’ and ‘mantissa’.
Characteristic: The internal part of the logarithm of a number is called its characteristic.
Case I: When the number is greater than 1.
- In this case, the characteristic is one less than the number of digits in the left of the decimal point in the given number.
Case II: When the number is less than 1.
- In this case, the characteristic is one more than the number of zeros between the decimal point and the first significant digit of the number and it is negative.