@article {MATHEDUC.06619339,
author = {Mahmood, Munir and Mahmood, Ibtihal},
title = {A simple demonstration of zero factorial equals one.},
year = {2016},
journal = {International Journal of Mathematical Education in Science and Technology},
volume = {47},
number = {6},
issn = {0020-739X},
pages = {959-960},
publisher = {Taylor \& Francis, Abingdon, Oxfordshire},
doi = {10.1080/0020739X.2015.1119896},
abstract = {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.},
msc2010 = {K20xx},
identifier = {2016e.00851},
}