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Overview
Advanced Mathematics 3200
Permutations Combinations and the Binomial Theorem
20. NL.SO.3200PCBT2
20.1 Factorial notation
Factorial Notation
n! means the product of n and every positive whole number below it, down to 1.
What You'll Learn
n! means n times every positive whole number below it, down to 1.
Example: 5! = 5 times 4 times 3 times 2 times 1 = 120.
Factorials grow very quickly as n increases.
By definition, 0! equals 1, not 0.
Factorials are the building block for permutation and combination formulas.
What You'll Practice
1
Evaluating factorial expressions like 5! and simplifying ratios like 7!/5!
2
Solving factorial equations and verifying solutions are valid
3
Arranging letters in words with and without repetitions
4
Calculating seating arrangements with restrictions (together, apart, alternating)
5
Finding circular arrangement counts using (n-1)! formula
Why This Matters
Factorial notation is fundamental to counting and probability, helping you solve arrangement and permutation problems efficiently. You'll use these skills in statistics, computer science, and higher math courses whenever you need to count possible outcomes or orders.
This Unit Includes
19 Video lessons
Practice exercises
Learning resources
Skills
Factorial Notation
Permutations
Arrangements
Counting Principle
Restrictions
Circular Arrangements
Repetitions
NL Curriculum Aligned