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Evaluating Algebraic Expressions
Order of Operations/
P.E.M.D.A.S.

The order and connection of ideas
is the same as the order and
connection of things.
Baruch (Benedict) Spinoza,
1623-1677, Dutch

• Solving linear equations
• Solving math word problems
• Evaluating algebraic expressions
  P.E.M.D.A.S. ◄
• P.E.M.D.A.S.: 2nd exercise
• P.E.M.D.A.S.: 3rd exercise
• Math tests
• Developing spreadsheets
  and budgets
• Math bibliography
  - web sites with on-line help

Second exercise
again, you do the math! (requires Flash)

Third exercise
Now you choose the order
but we'll do the math! (requires Flash)

Evaluating algebraic expressions can be a simple process,
but needs to follow an order of operations to get the right answer. 
The sequence details the order you follow to 
add, subtract, multiply, and divide.  The order is:

P.E.M.D.A.S.
Parenthesis | Exponents | Multiplication | Division | Addition | Subtraction

1. Perform the operations inside a parenthesis first
2. Then exponents
3. Then multiplication and division, from left to right
4. Then addition and subtraction, from left to right
5. You can also create a little phrase to memorize the sequence:
   Please Excuse My Dear Aunt Sally

An example:

3 * ( 5 + 8 ) - 2²  /  4 + 3

Parenthesis first:  5 + 8 = 13

3 *  13  - 2²  /  4 + 3

Exponent next: square the 2 or  2²  = 4

3 *  13  - 4  /  4 + 3

Multiplication and Division next (3 * 13) (4 / 4)
left to right:

39 - 1 + 3

Addition and Subtraction next
left to right:

39 - 1 + 3 = 41

Note that we first subtracted 1 from 39 (left to right!),
then added the 3 for the correct answer, 41.

Flash exercises contributed by Ingrid Noble and  Dr. Brad Hokanson,
Interactive Media (DHA 4384) School of Design, University of Minnesota.See also: 

Purplemath, the Order of Operations (1/19/05)

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