Notes 2-2a Order of Operations
1) An______________________________________ is a combination of variables,
numbers, and operations WITHOUT an equal sign.
Examples:
5+2x3
5b
g2 - 35
The value of a more complicated expression can depend upon the order in which you
do the operations.
Example:
7+3x2
7+3x2
2) We sometimes use __________________________ so that it is clear what should
be done first in an expression.
Example:
(7+3) x 2
7 + (3x2)
Besides parentheses, _____________________________ are also used to indicate
which operations should be performed first.
Example:
3+ 5• 2
34 3
3) To be sure that the order to perform operations is always clear, mathematicians
have established a set of rules called ORDER OF OPERATIONS. By
convention, they always perform operations in this order. You may have used the
mnemonic: Please Excuse My Dear Aunt Sally to remember the order.
4)
Please
Excuse
My Dear
Aunt Sally
P
E
MD
AS
Please Remember multiplication and division are equal in terms of order or importance.
Addition and subtraction are also equal.
We work from left to right, top to bottom applying order of operations along the way.
ALWAYS SHOW EACH STEP ON ITS OWN LINE
ONE operation per line, re-writing the rest of the expression each time
OVER
EXAMPLES:
2(6+4) – 3 x 5
32 − 22
÷ 2 + 98
7
23 − (4 + 2) ÷ 3 − 2
5 + 5× 4 6 + 6 ÷ 3
−
5
6−2