The significand or more ambiguously mantissa, Although the other names mentioned are common, significand is the word used by IEEE 754, an important technical standard for floating-point arithmetic. In mathematics, the term "argument" may also be ambiguous, since "the argument of a number" sometimes refers to the length of a circular arc from 1 to a number on the unit circle in the complex plane.
Example
The number 123.45 can be represented as a decimal floating-point number with the integer 12345 as the significand and a 10<sup>−2</sup> power term, also called characteristics, where he proposed the format n; m, showing the need for a fixed-sized significand as currently used for floating-point data.
In 1946, Arthur Burks used the terms mantissa and characteristic to describe the two parts of a floating-point number (Burks