22 Mastering the Calculator using the Casio fx-82MS
8. Factorial x!
Look at your calculator and find the key with the symbol x! on it. You will come across this
symbol when doing the Binomial Distribution. This is called the factorial key.
Use it to find the 3! and 5!. Press
3! means 3 × 2 × 1 and 5! = 5 × 4 × 3 × 2 × 1
3! = 6 5! = 120
How many ways would you guess that we could arrange ten people?
That is, how large would you estimate 10! to be? Use your calculator to find 10!
You should get 3 628 800.
10! = 10 × 9 × 8 × ... × 3 × 2 × 1
(Thank goodness this can be done on the calculator.)
Factorial rule
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
Use the shift key
to activate x!
To Next Page
Loading...
Need help?
General
Weight and Dimensions
