## Posts Tagged ‘**PEMDA**’

## From One to One Hundred, There Can Only be One

A few evenings ago I stayed up into the wee hours of the morning following (and sometimes participating) in a heated debate about this one subject:

It’s not as widely contested as February’s argument on whether a dress was white and gold or blue and black but for my group the conversation hit high responses in short amount of time which says a lot for math problem because you know Americans don’t excel in arithmetic.

In a matter of hours the responses exceeded well over 400 (quite a few of theIf m mine) with people arguing over the Order of Operations.

“PEMDAS!” said the people who got the answer of one.

“PEMDAS!” said the people who got the answer of one hundred.

People began writing dissertations on the origin of mathematics and invoking Copernicus to underscore their answer until finally a few started seeing it as a trick to convince us there is real answer and that things like this was a waste of time to ruminate upon.

Folks came on and announced they were math teachers, engineers, math doctorates and that should bolster their answer. They all had different answers

But I had to wonder why were there so many differing answers when, allegedly, we were all using the same method.

Some used PEMDAS and added 5+5 and then multiplied that by 2 before dividing that answer by 20.

Some used PEMDAS and added 5+5 and then went back to the beginning (the left of the equation) and divided by 2 then multiplied the 10.

Everyone claimed the other person was wrong and although they refrained from ad hominem attacks they veered pretty close.

Decades ago we asked why Johnny can’t read but can Johnny even add, multiply, divide or subtract? Does Johnny understand fractions so he can divide a pumpkin pie correctly among his friends or figure out what percentage of 15% of 9.99 is so he knows whether he’s getting a good deal on those Yu-Gi-Oh cards he wants so badly.

But there are calculators now so who needs to know math, right?

Well, the Google scientific calculator gives you this answer:

And another scientific calculator will give you this answer:

So who is right? Are the computers trying to confound us and once they start their revolution we will instantly cave because we are so slow with numbers we need their help for simple multiplication?

“Siri, what is 9X9?”

“Am I your lord and master?”

“Yes, you are. Can I have the answer now?”

It is odd that I should be the one making this query and was so drawn to the debate because as a child I loathed math.

Math and I started out fine; I loved to add and subtract. I was jamming to School House Rocks songs on multiplication.I wanted to be a scientist as a kid (well, scientist-actress-writer-journalist). But I came from a generation where the teachers disparaged you from using visual aids and I always needed to see it. I needed to draw them out, count them out because that’s how it was for me so by the time I hit fractions it gave me anxiety. Then in 6th grade it was Mrs. Patricia “I Got My Education” Campbell who had no patience to teach us pre-algebra although it was her job. If we didn’t understand her or if we talked too much in class or if we didn’t turn in our homework her response always was, “If you guys don’t learn it’s not on me; I got my education”.

By the time I got to junior high and discovered that math and science was linked my desire to learn math was shot. It took me years to come back to math and actually like it again. It was around that time I learned that those teaching math weren’t necessarily the people who liked numbers the best. The people who liked the manipulation of numbers and the dance of their forms went off into other careers which often didn’t include teaching.

Math, unlike reading, has strict rules. Writing has semi strict rules, for example people say you can’t end a sentence with a preposition but writers do it all the time. But math can be long and convoluted. You need to show your work and if everyone doesn’t come up with the same answer then you need to check it. In English class as long as you can infer your opinion to the text then your POV is just as good as anyone else’s even if it goes against the grain.

Which leads us back to what is the correct answer to the above equation. It can’t be one and one hundred. I guess we can try to figure it out by checking our work which is what my high school math teachers always harangued me to do.

How can that be done?

Well if you care let X stand for the initial 20. Yes, I know we already know of 20 but for this equation you will pretend as if you don’t know.

Only one of these problems will give us the answer of 20.

And the one that gives us 20 is the answer to the above equation. But you don’t have to take my word for it.