mantissa vs fixed-point part

mantissa and fixed-point part both are nouns.

Word	Noun	Adjective	Verb	Adverb
mantissa	Yes	No	No	No
fixed-point part	Yes	No	No	No

As nouns, mantissa and fixed-point part are synonyms defined as:

mantissa and fixed-point part: the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808

mantissa (noun)	fixed-point part (noun)
the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808	the positive fractional part of the representation of a logarithm; in the expression log 643 = 2.808 the mantissa is .808