Drexel dragonThe Math ForumDonate to the Math Forum

Ask Dr. Math

Middle School Archive

Dr. Math Home || Elementary || Middle School || High School || College || Dr. Math FAQ

This page:
  factorials checkmark

  Dr. Math

See also the
Internet Library:


About Math

   factoring expressions
   graphing equations

   factoring numbers


     conic sections/
   3D and higher



Number Sense
   factoring numbers
   negative numbers
   prime numbers
   square roots

Word Problems

Browse Middle School Factorials
Stars indicate particularly interesting answers or good places to begin browsing.

Selected answers to common questions:
    Table of factorials, 1!-30!

Given a Factorial, Find the Number [05/02/2003]
How can we find a number if the factorial is given?

Smallest Value of N!; Factorial Table [11/07/2001]
If N! ends in exactly 3 zeros, what is the smallest possible value of N?

What Is N Factorial Used For? [08/29/2001]
I have heard that it is used in probability, but what for, and how?

x Factorial and the Gamma Function [05/29/1998]
What is x! when x is 0, negative, or not a whole number?

Choosing 3 of 6 Colors [03/03/2000]
Patrick has a box of crayons with red, blue, yellow, orange, green and purple. How many different ways can Patrick select 3 colors?

Circumference of a Circle, Value of 5! [5/15/1996]
The area of a circle is 16 pi. What is the circumference of the circle? Also, what is the value of 5!?

Combinations of Coins [1/28/1996]
If I had 6 coins in my pocket, how many combinations could I have?

Decimal Places in Large Factorials [04/29/2003]
Is there an easy way to find how many decimal places or how many zeros the decimal notation of a large factorial number will have?

Derivative of x! [05/27/2003]
My Pre-Calculus teacher gave my class several derivative practice problems to do in our spare time, one of which is: (d/dx)(x!).

Double Factorial [02/22/2002]
Can you tell me what two ! marks mean in factorial questions?

Factorial [4/1/1996]
What is factorial?

Factorials [11/15/1994]
One day when I was playing on a calculator, I found that 1 and 0 both have a factorial of 1. Can you explain this?

Factorials [02/07/1998]
How do you find the number of zeros at the end of a number factorial? For example, 100! or 130!

Factorials [2/3/1996]
What does 3! mean?

Factorials and Order of Operations [09/21/2000]
Where do factorials go in the order of operations?

Factorials of Negative Integers [06/27/2002]
Is it possible to compute factorials for negative integers?

Find the Last Eight Digits of a Factorial [1/30/1996]
Find the last eight digits of 69! where 69!=69x68x67........x1

Given x!, Find x [12/21/2002]
If the value of x! is given, how do we find the value of x?

Googol Factorial [11/09/1996]
What is googol factorial?

How Big is a Googolplex? [05/29/2003]
Is there anything on Earth that is as big as a googolplex?

How to Evaluate 4!!!! [10/16/2003]
Our Calculus 2 teacher has challenged us to find the exact value for 4!!!!, but the number is too large to reasonably calculate by hand.

An Informal Argument for Why 0! = 1 [01/13/2008]
I don't understand why 0! equals 1. Can you explain it?

Odd Factorial [12/24/2001]
Can a factorial ever be odd?

Origin of the Factorial Symbol ! [01/14/2002]
My students would like to know the origin of the mathematical symbol for factorial - !.

Representing a Number [10/29/2001]
How can you represent the number three without using any letters or variables or the digits 1 through 9?

Six Billion Factorial [05/15/2003]
6 billion p 100. I know how to do permutations but there must be a quick way to do a problem like this.

Zero Factorial [05/24/1999]
Why does 0! = 1?

Page:  1

Search the Dr. Math Library:

Search: entire archive just Middle School Factorials

Find items containing (put spaces between keywords):
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

[Privacy Policy] [Terms of Use]

Home || The Math Library || Quick Reference || Search || Help 

© 1994- The Math Forum at NCTM. All rights reserved.