Calculating a Permuation
In mathematics, to calculate the permutation of n things taken r at a time, we use the formula. The TI-83/84 has this formula already built in.
To calculate , on the home screen first press the MATH key. Next press the RIGHT ARROW key three times so that PRB is highlighted. Press 2 to select the permuation formula then type 10, press RIGHT ARROW, then type 7 and press ENTER. The results are shown below.
Thus, = 604,800.