Solution 11703: Calculating Factorials (!) on the TI-83 Family, TI-84 Plus Family or TI-Nspire™ Handheld in TI-84 Plus Mode.
How do I calculate factorials (!) on a TI-83 family, TI-84 Plus family or TI-Nspire Handheld in TI-84 Plus mode?
The example provided below will demonstrate how to calculate factorials on a
TI-83 family, TI-84 Plus family or TI-Nspire handheld in TI-84
Example: Compute 5!
1) Press .
2) Press [MATH], scroll left to select PRB and press  to select the ! operator.
3) Press [ENTER] for the result.
Please see the TI-83 family and TI-84 Plus family guidebooks for additional information.
Please Note: TI-Nspire handheld in TI-84 Plus mode users may refer to the TI-84 Plus family guidebook.