Understanding Factorials (n!)
Objective: Learn how factorial notation is used to count arrangements and compute products of positive integers.
Factorials (n!)
Definition:
n! = n x (n - 1) x (n - 2) x (n - 3) x ...x 2 x 1
Example: 3! = 3 x (3 - 1) x 1 = 6
Calculate the value of 5!
This applet introduces factorial notation and allows students to practice calculating factorials through a multiple-choice question.
Teachers can use this activity to introduce factorial notation and counting principles. Students solve the factorial problem and then review the explanation to reinforce their understanding.
How to use Applet?
1. Read the definition of a factorial.
2. Study the worked example.
3. Solve the multiple-choice question.
4. Check the explanation to verify your answer.
Explanation:
The correct answer is C. 120
5! = 5 x 4 x 3 x 2 x 1= 120
or
5! = 5 x (5 - 1) x (5 - 2) x (5 - 3) x 1 = 120