\input zb-basic
\input zb-matheduc
\iteman{ZMATH 2016e.00851}
\itemau{Mahmood, Munir; Mahmood, Ibtihal}
\itemti{A simple demonstration of zero factorial equals one.}
\itemso{Int. J. Math. Educ. Sci. Technol. 47, No. 6, 959-960 (2016).}
\itemab
Summary: When asked, a number of students answer zero factorial to be zero as a continuation to the answer of one factorial to be one. Any instructor would then seek a justification of zero factorial to be one from computing ${}_nC_n$ via the well-known combination formula. This article conveys a simple presentation of zero factorial to be one based on lower and upper bounds of $n$ factorial. We have not seen this explanation covered in any algebra textbook.
\itemrv{~}
\itemcc{K20}
\itemut{factorial; bound; limit}
\itemli{doi:10.1080/0020739X.2015.1119896}
\end