# How do you calculate permutations on the TI-84?

Jan 13, 2015

It's on one of the stat-var menus. It's called $n P r .$

You first enter the larger number $n$ (the number of cases to choose from), then you enter the $n P r$ function, and then the number to be chosen $r$.

You use $n P r$ if the order of selecting is important.

If that isn't the case, you use $n C r$ (C for combinations) in the same menu.

Extra:
You will find that nPr=nCr *r!

(the ! in r! means 'factorial' and is a multiplication of all numbers up to and including $r$, so 4! =4*3*2*1=24)