Microsoft Excel™’s default method of displaying probability values observed in the sample, in the case of very small values, is confusing to beginning students in statistics. This is because Excel displays them in engineering notation (3.52955E-.05, as opposed to .0000352955, for example). In addition, high quality statistical software programs, such as SAS/STAT™, never display an actual default probability value as small as .0000352955. For any probability value in a sample less than 1-in-10,000, SAS will display the given probability value as <.0001.
Larson, David A. and Rogers, Sylvia E. Ms
"Improving How Microsoft Excel Displays Default Extremely Small Probability Values,"
Spreadsheets in Education (eJSiE):
3, Article 6.
Available at: http://epublications.bond.edu.au/ejsie/vol5/iss3/6