Lisanne

You had a truly lousy math professor. "Follow the rules, don't bother trying to understand them" isn't teaching. That kind of attitude is what caused me to have so much trouble with math prior to algebra, when I finally got a teacher who was willing to hear me say things like your bounced check example and explain the concepts so I understood them.

So let's talk about negative numbers.

Barb, in your example, you were adding negative numbers, not multiplying them. And you're comparing a negative to a bad deed. It's not the same as the saying "two wrongs make a right."

Adding a negative - or two or more negatives - is just subtracting from whatever was there to start with. If your bank account is empty and you write a check for $35 and another one for $40, that's:
0 + (-35) + (-40) = -75
or 0 - 35 - 40 = -75
You are $75 in the hole (plus bounce fees)

If you had $5 in your account to start with and wrote those two checks, it would be:
5 - 35 - 40 = -70.

Okay, multiplication. In the real world, whether a number is negative or positive all depends on how you look at it.

Say I'm throwing a quilting party for all my quilting friends, and I decide to give out bundles of fat quarters as a party favor. I'm inviting 8 friends and I want to give each one 3 bundles of fat quarters (tied together with a ribbon).
8 x 3 = 24
So I know I must buy 24 at the store or cut up 24 fat quarters from my stash, or whatever.

Okay, those are both positive numbers, so you all knew how to do that.

But it's how you look at it. Same story, but I'm taking the fat quarters from my stash, and I'm thinking how many fat quarters will be lost from my stash. So this time, it's:
8 x -3 = -24
where the negative is what's lost from my stash. I'll be down 24 fat quarters.

Let's change the story a little. Instead of fat quarters as a party favor, they're going to be donated to making charity quilts. Since each person is donating, each person is losing those fat quarters, so now the 8 is negative, too.
-8 x -3 = 24
8 people have given away something. They gave away 3 fat quarters each. But now you have a marvelous quilt from the 24 fat quarters! The 24 isn't a deficit, it's a positive. Sort of a "Your loss is someone else's gain" kind of thing.

Okay, that was probably a terrible example. Let's go back to the bounced checks. Say your bank charges a fee of $25 each time you bounce a check. You bounced two checks.
From the bank's point of view: 2 x $25 = $50
They made $50 off you.
Exactly the same thing, from your point of view:
2 charges x -$25 = -$50
It's more money you have to pay, so you're down the $50.

Let's say you go in and sweet-talk the manager into removing the charges. You've been a good customer for years, this is the first time it ever happened, there was a good reason, and you batted your eyelashes prettily, so he agrees.
Again from your point of view:
-2 charges (because they're being removed) x -$25 (what you were losing) = $50 (because now you can put the $50 back in your wallet)

Bleah! My 7th grade teacher explained this in terms of photographic negatives...

barnbum

Lisanne!! You're a great teacher!! :-D

IrishNY

Just make sure that the minute you feel like you're getting lost, go to the math center or get a tutor. If you can stay caught up, you'll be fine. What a wonderful opportunity - enjoy it!

Shibori

I barely made it through. All I remember is a+b=c or something like that which translates in to children+mud=insane mom. Shows how I applied algebra to my life :)

barnbum

:lol: :lol: :lol: :lol: :lol: Great thinker!!

Lneal

Thanks lisanne, I am taking your explanation in!! :thumbup:
I found this little saying to the tune of row row row your boat.....

Same sign keep and add, different signs subtract
Keep the sign of the higher number
Then it will be exact!

that sounds like baby steps I know but I actually find myself repeating it when I can't remember what to do. I hope I grow up soon and this algebra sticks in my head :lol:

Bobbinwinder

I'm always in favor of furthering education...and I understand required courses for particular degree plans, and if you don't mind sharing what you're hoping to do with your college education, I'd love to hear your plan/goal. Being a non-traditional age student is something I've experienced.

wvdek

Lneal congrats! You go! You can do it. What are you going to major in?
I went back to school last year at the age of 53. When I graduate I will be 56. I am taking Medical Assisting because I missed the LPN program by 5 lousy (math) points. Everything else was ok.
I don't dislike math at all-I just don't get it.
Will have to have a special tutor nest semester to get through Math 102 in order to get my degree.
Anyway, I was alway's a C student but this last semester I had a 3.66 GPA. I was ecstatic. So, if I can do it you can to.
We may need to hire Lisanne to be our teacher though. Putting it into quilt terms made more sense. LOL

Lisanne

What a great little rhyme that is! That will work very well. You're off to a fine start!

You're too kind. That is wonderful, coming from a real teacher!

I'm not at all happy with those examples. If I could remember any story problems along these lines, it would be better. In physics, where it's practically all story problems, you get very, very comfortable with handling negatives, fractions, decimals, percentages, everything.

Congratulations on your great grades! It really is a shame that you missed out on getting into the LPN program because of math, and by such a small amount of points. Oh well, the world needs more medical assistants, too. (You can always spiff up your math and go back later for an LPN or RN program.)

And if I can help, please feel free to ask.

Lneal

I will be doing a two year program with a degree in Business Administration. I didn't do well enough on the math for the placement test so I must take a pre algebra class. My orientation is in two weeks and I am a little nervous. It's interesting to know there are others my age who are going to college too
:D