22
Mastering the Calculator using the Sharp EL-531LH
Factorial rule
9.
Using memory
To calculate the following it may be useful to use the memory key for each term:
Example:
The number of ways of arranging n items in order is known as ‘factorial n’ which is
symbolised as n! where:
n! = n
×
(n – 1)
×
(n – 2)
×
...
×
3
×
2
×
1
9
16
–
(
)
2
16
----------------------
23
16
–
(
)
2
16
-------------------------
17
16
–
(
)
2
16
-------------------------
+
+
these keys are for memory
