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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