The only bit of math I have retained is that order in which you solve expressions, only because it fits neatly in the language hemisphere of my brain because of the mnemonic device “Please Excuse My Dear Aunt Sally” (Parentheses, Exponentials, Multiplication, Addition, and Subtraction. Spoiler: This is a lie.)
I can remember the mnemonic because my left hemisphere works. I would comfort myself that math pros can do the math but can’t remember the mnemonic. Hahahaha: justice. Then I remember Friend #4 who can write and calculate in her head simultaneously.
So, intermittently on Facebook you’ll see a question like this:
Then, in the comments you’ll see a variety of answers, each insisting they are right. I felt confident I could get it right, because I had my dear Aunt Sally to guide me, especially since there were no parentheses or exponentials. (It’s odd that in English a parenthesis connotes a topic is less important; in math it is most important. I wonder if people who use both hemispheres read this parenthetical statement at the top of their lungs instead of the confidential tone I use to write it.)
I wasn’t brazen enough to share my answer the entire world on Facebook; I just sent it to Friend #4, and let my friends see it.
Five, I said.
Hot Mom immediately commented that she and her eleven year old daughter both got seven, how did I get five?
I replied:
My: 6-(0)+2/2
Dear: 6-0+(1)
Aunt: 6-(1)
Sally: 5
Logic!
Friend 4 replied that no, seven, and here is why:
P – Parentheses – Left to right, solve all parentheses first.
E – Exponents – Left to right, solve all exponents.
MD – Multiplication and Division – Left to right, solve all multiplication and division in the order they appear. They have equal weight, so do not skip division to do multiplication later in the expression.
AS – Addition and Subtraction – Like MD, they have equal weight, so solve them left to right.
This concerned me, not only because now I can’t do fourth grade math, but I was concerned about the Middle East and wherever else they read right to left. How confusing must that be? They would be hard pressed to answer five as well, because the subtraction is on the right.
What we need is a new mnemonic, one with four words instead of six. (I almost wrote “seven words,” then I counted on my fingers.) But in the third word, there must be an M and a D, in that order (left to right). Similarly, the fourth word needs to have both an A and an S.
I’ve got “Please excuse MacDuff’s ASpirations,” which doesn’t make sense because it was the Macbeth’s who were ambitious. “Parents enjoy McDonalds’ …. Apple Snacks?” No that’s two words. AppleS? No, that S is too easy to ignore.
Piggies Exhibit McDonalds Ass?
I like that one but it won’t play to the fourth graders. It’s too declarative as well. Aunt Sally had a little mystery to her.
10 responses to “Please Excuse My Dear Aunt Sally, She is a Psycho Bitch”
I answered 1 and was sure I had it. I hate hate hate math. I used aunt sally and still got the wrong answer. If there is a story problem at the pearly gates I am so screwed.
You were fine with your mnemonic, and it doesn’t need changing. Where you went wrong was that you added mental parentheses where they didn’t belong, and you forgot that the “+” and “-” signs, in the absence of parentheses, belong to the numbers they precede.
My: 6-0+2/2
Dear: 6-0+1
Aunt: 6+1
Sally: 7
In “Dear”, -0+1=1. The minus belongs to the 0, different from -(0+1)
You are WAY better than I am at math. I couldn’t even take a shot at that problem.
However, here’s what I have noticed. In the office where I work, and in most of life in general, people who can solve difficult algebra problems don’t seem to have any real day-to-day advantage. People who can write well, however, have an enormous advantage on a daily basis. I’m sure there are exceptions, like if you happen to be an engineer, but for most things, no. If you can handle money calculations, you’re covered.
Zayrina – I think 1 should be an answer, and negative 1 should be an answer in the middle East.
~~Silk – so I could add negative numbers and not call it subtraction? Sounds too disingenous to me.
Teri – Sadly, I know people who are good at math and writing, and worse, I know people who are pretty and smart. Even worse, I am fat and competitive.
Yes. You don’t divide; you multiple fractions. You don’t subtract; you add signed numbers.
While Silk is a member of MENSA I remain a lifetime member of DENSA.
As a matter of fact, I do read parentheses at full volume. To me they are more of an interesting aside than less important note.
~~Silk – I’m trying to think of how division is fractions – oh wait. That’s why they use the slash sign for both. Eureka.
Zayrina – Ha!
Caroline – No. That is all wrong. Okay, Tuesday I;m having peoplke read some parenthtical phrases to you (so you can hear how they’re supposed to sound).
I typed 5 by accident, then thought about posting that, “Wait, I know it’s 7, don’t look at that 5!” And then I thought, “What’s wrong with you?” and moved on.
Tami – I saw your “five” and was encouraged my five might be right.