Understanding Factorials for Grade 8

Front

Definition of Factorial

Back

Product of all positive integers up to a number

Front

Notation for Factorial

Back

n!

Front

0!

Back

1

Front

5!

Back

5 × 4 × 3 × 2 × 1 = 120

Front

Recursive Formula

Back

n! = n × (n-1)!

Front

Factorial of 1

Back

1! = 1

Front

Factorial Growth

Back

Grows very fast as n increases

Front

Use in Combinations

Back

nCr = n! / (r!(n-r)!)

Front

Use in Permutations

Back

nPr = n! / (n-r!)

Front

Factorial of 3

Back

3! = 6