Finding common logarithm of any number

In numerical calculation, the base of logarithm as 10.this logarithm is called common logarithm or Briggesian logarithm in honor of Henry Briggs Finding common logarithm of any number: (1) Round off the number to four significant number (2) Find the characteristic of the logarithm of the number by inspection.(3) Find the mantissa of the Logarithm of the number from the table.(4) combine the two.

Finding common logarithm of any number


(i) Log 276.23

(ii) Log o.07058


(i) 278.23 round off as 278.3

here characteristic is 2 and the mantissa,

by using Log table is 0.4443

Therefore, Log 278.23 = 2.4443

Example:Finding common logarithm of any number

(ii) Log .07058


Characteristic of the Log 0. 07058 is -2 Which is written as.

By using Log table, the mantissa is 0.8487 so that

Log 0.07058 = 2‾. 8487

common logarithm and natural logarithm:

Common logarithm having base 10. Common logarithm also known as  decadic logarithm after its base 10. We usually take log x this has mean log ₁₀ x, and this type of logarithm is more convenient to use in numerical calculation. John Napier prepared the logarithm table to the base e. Napier logarithm are also called natural logarithm. He released the first ever log table in 1614. log x conventionally given the Notation ln x.

Value of e:

e is an irrational number whose value is 2.7182818…..