Mantisa or Mantissa: How To spell?
The word Mantisa is misspelled against Mantissa, a noun meaning "The decimal part of a logarithm, as distinguished from the integral part, or characteristic."
Mantissa has double "ss" is mispronounced as "s"Remember double 'SS' in between the strings manti & a which should not be misspelled with single 'S'
Wrong Spelling:  manti-s-a  Correct Spelling:  manti-ss-a 
Find more wrongly spelled words of Mantissa to spell it well.