Lg is shorthand, and log is logarithm based on 10, which can be shorthand. Also known as "decimal logarithm". LgA stands for the logarithm of a based on 10, where a is a real number. The common logarithm of any positive number can be expressed as the sum of an integer and a positive pure decimal (or zero); The integer part is called the "first number" of logarithm, and the positive pure decimal (or zero) is called the "mantissa" of logarithm.

What does lg mean? To understand the meaning of lg, mathematics must first understand what logarithm is.

For example, the third power of 2 equals 8. On the contrary, finding the power of 2 is equal to 8. This calculation is called logarithmic operation. Obviously, the answer to the question just now is 3. Therefore, we call 3 the logarithm of 8 based on 2. Written as: log2 (written in the lower right) and 8 (written in the upper right). Note: Negative numbers and zero have no logarithm.

For the convenience of representation, the logarithm based on 10 is denoted as LGX(x >；; 0)

Write the logarithm with irrational number e as lnx(x >；; 0)