Entry in progress—B.P.
OCLC WorldCat record
Please, My Dear Aunt Sally
Author: Richard W Shoemaker
Edition/Format: Article Article : English
Publication: The Arithmetic Teacher, v27 n9 (19800501): 34-35
Database: JSTOR Mathematics & Statistics Collection
Google Groups: alt.callahans
A few of my favorite words
“Please Pity My Dear Aunt Sally: Parens Powers Mult Div Add Subtract; order of
precedence in elementary arithmetic.
Please Excuse My Dear Aunt Sally (PEMDAS)--Forever!
By David Ginsburg on January 1, 2011 10:21 PM
You don’t have to be a math whiz to know that 4 - 2 + 1 equals 3. Yet I was working with several students recently who said it equals 1. And it wasn’t their fault. Nor was it their teacher’s fault. Nope, the blame in this case and in countless similar cases I’ve encountered over the years rested squarely with the fictitious Aunt Sally of “Please excuse my dear Aunt Sally” (or PEMDAS: parentheses, exponents, multiplication, division, addition, subtraction) fame--the acronym intended to help students remember the order of operations.
The problem with PEMDAS is that it excludes the “from left to right” requirement for multiplication and division (#3 below) and addition and subtraction (#4 below). Students, as a result, think multiplication always precedes division and addition always precedes subtraction. This explains why students in the above example said 4 - 2 + 1 equals 1 rather than 3 (i.e., they simplified 2 + 1 first rather than 4 - 2).
@fanoonman Order of Operations in math. PEMDAS. Please Excuse My Dear Aunt Sally. Parentheses, Exponents, Multiply, Divide, Add, Subtract.
6:21 PM - 24 Dec 2016 from Phoenix, AZ