Calculating Factorials Using a Scientific Calculator

Scientific calculators simplify the process of inputting and calculating more complicated expressions than standard calculators. Ordinary calculators can handle factorials, but you have to enter them manually, and this can be time-consuming if you’re taking the factorial of a bigger number. Scientific calculators make this much easier, with most of them including a “x!” key purpose-built for evaluating factorials. All you have to do is enter the number you want to take the factorial of and then press this key to evaluate it.

TL;DR (Too Long; Didn’t Read)

Find the factorial of a number on a scientific calculator, enter the number and press the “_x_!” key. This may require you to press “shift,” “2nd” or “alpha” first depending on your model of calculator and the location of the symbol. Press “=” to get the result.

What Is a Factorial?

Factorial is the name given to the process of multiplying together all of the integers up to a certain number. So 5 factorial is 1 × 2 × 3 × 4 × 5 = 120 and 3 factorial is 1 × 2 × 3 = 6. Notice that a small increase in the number you’re taking a factorial of can lead to much bigger answers. The symbol for a factorial is x!, where x is the number you want to take the factorial of. For 4! you can say “four factorial,” though you may also hear the occasional “four bang” or even “four shriek.”

Factorials on a Graphing Calculator

On graphing calculators, you may need to do even more to do a factorial. For example, on the TI-84 Plus, you need to enter the math probability menu by pressing “[math]” followed by the left key twice, and finally press “4” to enter the factorial symbol. Check your manual to find the way to complete the operation on a specific graphing calculator.****