[Wondergirl]

But we're not in computer class. We're doing high school algebra here.

(-4)(-3) ÷ 6 - 2[5 - -8 + (6 ÷ 2)]
(-4)(-3) ÷ 6 - 2[5 - -8 + (3)]

[5 - -8 + (3)] means [five minus negative eight plus three]

Right?

[KISS]

Right.

We are not in high school here. We are in Elementary school. 5 - - 8 can be don on a NUMBER LINE.

Draw number line.
Put pen on -5
With the minus operator go negative
With the unary - operator reverse direction again
So, you moved 8 units in the positive direction from -5.

This is Elementary School stuff.

[Wondergirl]

No, not the unary verbiage. Skip that part.

[5 - -8 + (3)] means [five minus negative eight plus three]

Right? Or wrong?

[KISS]

I said right.

[Wondergirl]

I said right.

Thanks!

[morgaine300]

I've never heard the word unary either, and no, this isn't a computer class.

It's also not elementary school for someone who went to school 40 years ago! Not all elementary schools even today get into this type of thing, let alone that many years ago. Stop making it sound like "baby stuff" that everyone "should" know.

WG, there was nothing wrong with the way you started this. I don't even know what all the jibberish that followed it was about. You can do the division you did first with no problem.

From there you have several choices. I would have solved the brackets on the right first like Unky did.

5 - - 8 + 3 does indeed equal 5 minus negative 8, but you're coming out with the wrong answer to that. Minus does mean go left on the number line (subtract), but you're minus'ing a negative 8, which puts it back the other direction, to the right. It's like saying the - on the 8 means "go the opposite direction as what you would have otherwise." "Minus a negative" is actually adding. So it's 5 + 8 + 3 = 16.

[KISS]

I was in elementary school too 40 years ago and I swear we had this stuff.

[Wondergirl]

I was in elementary school too 40 years ago and I swear we had this stuff.

I TAUGHT elementary school that many years ago and didn't teach it. I asked my husband who went to "mid- to upper class" Chicago suburban schools, and he had never heard of it either. He builds his own computers and is retired from Western Electric/Lucent as a 5ESS installer and never heard of it there either.

[KISS]

I don't expect anyone to know about Unary minus. Wikipedia mentions how elementary school elude to it.

I've written operating systems as part of a class project and I built a computer when the 8008 was out using just using 7400 series gates as part of a lab with 2 other people. The "computer" couldn't do much but sort 16 numbers, but it was a computer.

In high school I did know about unary minus though because I was involved with computers before the IBM PC. I also took a computer college class and two of my mentors were brothers that were in high school as well and eventually went to MIT. They essentially ran the state's time-sharing network into the high schools. I hacked the system and eventually worked on their side preventing breaches.

Generally, you don't learn about interpreters and RPN until you start taking courses in programming or writing compilers and interpreters. I've written in many machine languages for different processors.

I don't expect it to be taught as Unary minus, but I do know I could add, subtract, multiply and divide by high school.

[Wondergirl]

I don't expect anyone to know about Unary minus. Wikipedia mentions how elementary school elude to it. I don't expect it to be taught as Unary minus, but I do know I could add, subtract, multiply and divide by high school.

Elementary schools allude to it, but don't call it that. And yes, we all could add, subtract, multiply, and divide by high school. At least, most of us could. Those negative numbers can be real tricky. I'm not so sure about how well students today can do basic arithmetic, much less algebra, from what I've seen of teen library volunteers.

[Wondergirl]

And thank you, KISS, for telling me about something (and leading me to research it) that I had never heard of before. I always like to learn new stuff.

[KISS]

Your quite welcome.

Did you know Google does some math: e.g. Google

[Wondergirl]

Google is my middle name, but I didn't know about that Google function. I bookmarked the Search page for future reference. I owe you another thank you.

[morgaine300]

I'm not so sure about how well students today can do basic arithmetic, much less algebra, from what I've seen of teen library volunteers.

Hmm, yeah, well don't forget I work with college students... and a few weeks ago I ran across someone who didn't know what half of 6 was. So there you go. :rolleyes: