Factorials are noted with the use of an "!," so the format of a factorial is x!. A factorial multiplies together all the numbers preceding the number in the factorial. For example, if you have 4!, it means 1 times 2 times 3 times 4. Using a scientific calculator, you can perform the calculation without needing to break the factorial down and multiply the individual numbers together. On a sceintific calculator, the factorial button is "x!."
Type the number in the factorial. For example, if your factorial is 4!, then type "4."
Press the "2nd" key or "Shift" key. If your factorial button is a primary button, then you do not need to access the secondary features on the buttons.
Press the "x!" button. The calculator then solves the factorial.