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Thank you for this whole thread Pam!!!
Whether or not I ever use the negative/positive IRL matters not a bit to
me....I have another tool at my disposal and I'm really grateful for that.
Because you just never know.
It seems to me that at the edge of my consciousness there is this little
tickling going on, like I can almost understand why you would use that to
explain stuff irl, but then it just goes away.
I'm not quite there.
I still need to sit and read it over again to really let this all sink in.

It seems that the positve/negative thing could be useful to just explain
relationships between things? But I'm still so math phobic I actually get a
ball of frustration ( I can physically feel it) in the pit of my stomache.
I have to really put an effort forth just to read the type of post you used
to explain this.
And yet, I find it fascinating.
Fascinating that there is real math, useful ways to learn this, not the
stressful experience that was mine in school.
Just writing this makes me get that feeling in my gut....very uncomfortable.
The word "math" does it to me.
Thank you for helping us nonmathies!!!!

I provide tools for my kids, but so far they are very self taught....I really
want to be more creative with my use of numbers to be more help to them!!
Keep it coming....please.
I need math therapy.
Ren

Fetteroll

on 5/8/02 1:02 AM, starsuncloud@... at starsuncloud@... wrote:

> It seems that the positve/negative thing could be useful to just explain
> relationships between things?

Exactly!

In fact that's what *all* (or lots) of math is. Math helps us to compare
things, to see how two things relate to one another, how changing one thing
affects the whole thing.

If, for instance, you're traveling from Tampa to Miami, if you set your
reference (zero) point at Tampa, you'll know how far you are in relation to
Tampa. That isn't really very useful. But if you set your reference point as
Miami, then you know how many more miles you have to go.

With positive and negative numbers you get more information than just how
far it is related to the zero point. It tells you *where* -- which side --
in relation to the zero point. So if a train engineer tells the dispatcher
they're broken down 10 miles from Miami that isn't enough information for
the dispatcher to send out a repair crew. But the plus or minus (or east or
west, or before or after (which the dispatcher will need to *relate* to
which way that particular train is heading) - those are all just different
ways of telling where) tells the dispatcher which side of Miami they're at.

It's even more useful when you get x-y coordinates -- which is shut down
time for some people ;-) -- so you can locate things on the surface of the
earth (or the moon or Mars) rather than on a train track.

Say you wanted to tell a robot how to get to a meteor that hit Mars.
(Admittedly not an everyday household use, but nonetheless a real life use.
;-) Telling the robot the meteor hit 5 miles from the robot's landing site
on Mars means it could be *anywhere* on a circle of points that are 5 miles
from the landing point. But saying it hit 4 miles east and 3 miles north
precisely identifies exactly one of those points. Or 4 miles east and 3
miles south pinpoints another unique point.

(Choosing the landing site as the zero or reference point is just for
convenience sake. It's just whatever will make talking about hoe onr thing
relates to another easiest. What reference point to choice would be obvious
to anyone actually immersed in a real life problem because you'd know what
information you wanted and what you wanted to do with it. Which is a major
weakness of made up problems because you aren't gathering and manipulating
and *relating* the information for any real personally meaningful reason.)

If we say that north and east are positive and south and west are negative.
(Again, choosing that is *just* another convention because it's less
confusing. There's nothing negative about south or west. It's just
convention to put North up and East right, South down and West left. And
it's just convention to put positives to the top and right and negatives to
the bottom and down. Being conventional just makes communicating less
confusing.)

So we can say the meteor is at coordinates 4,3 for the north east one and
-4,3 for the south east one. (And 4,-3 would put it in the north west
quadrant and -4,-3 would put it in the south west quadrant.)

All that does is tell the robot how the meteor's location relates to the
zero point set at the landing zone.

Of course nonmathies would say why not just stick with north, south, east
and west. ;-) For *that* example with the robot sitting at the landing site
the north-south reference is probably easier to understand than x-y
coordinates and therefore better. *But* if you start needing to know
something about -- relate -- the distance between two meteors rather than
between one meteor and the zero point, or relate the distance between where
the robot is and where it wants to go, or relate how far the robot who has
moved from the landing zone is from each meteor to figure out the closest
meteor, then the positive and negative numbers make the calculation
incredibly easy.

Joyce

Karin

Thank you Joyce, for this explanation.
It's beginning to sink in now.
It definitely leaves a "friendlier" impression in my brain about positive
and negative numbers.
I think some of the math wall is starting to crumble. :-)

Karin




>
> > It seems that the positve/negative thing could be useful to just explain
> > relationships between things?
>
> Exactly!
>
> In fact that's what *all* (or lots) of math is. Math helps us to compare
> things, to see how two things relate to one another, how changing one
thing
> affects the whole thing.
>
> If, for instance, you're traveling from Tampa to Miami, if you set your
> reference (zero) point at Tampa, you'll know how far you are in relation
to
> Tampa. That isn't really very useful. But if you set your reference point
as
> Miami, then you know how many more miles you have to go.
>
> With positive and negative numbers you get more information than just how
> far it is related to the zero point. It tells you *where* -- which side --
> in relation to the zero point. So if a train engineer tells the dispatcher
> they're broken down 10 miles from Miami that isn't enough information for
> the dispatcher to send out a repair crew. But the plus or minus (or east
or
> west, or before or after (which the dispatcher will need to *relate* to
> which way that particular train is heading) - those are all just different
> ways of telling where) tells the dispatcher which side of Miami they're
at.
>
> It's even more useful when you get x-y coordinates -- which is shut down
> time for some people ;-) -- so you can locate things on the surface of the
> earth (or the moon or Mars) rather than on a train track.
>
> Say you wanted to tell a robot how to get to a meteor that hit Mars.
> (Admittedly not an everyday household use, but nonetheless a real life
use.
> ;-) Telling the robot the meteor hit 5 miles from the robot's landing site
> on Mars means it could be *anywhere* on a circle of points that are 5
miles
> from the landing point. But saying it hit 4 miles east and 3 miles north
> precisely identifies exactly one of those points. Or 4 miles east and 3
> miles south pinpoints another unique point.
>
> (Choosing the landing site as the zero or reference point is just for
> convenience sake. It's just whatever will make talking about hoe onr thing
> relates to another easiest. What reference point to choice would be
obvious
> to anyone actually immersed in a real life problem because you'd know what
> information you wanted and what you wanted to do with it. Which is a major
> weakness of made up problems because you aren't gathering and manipulating
> and *relating* the information for any real personally meaningful reason.)
>
> If we say that north and east are positive and south and west are
negative.
> (Again, choosing that is *just* another convention because it's less
> confusing. There's nothing negative about south or west. It's just
> convention to put North up and East right, South down and West left. And
> it's just convention to put positives to the top and right and negatives
to
> the bottom and down. Being conventional just makes communicating less
> confusing.)
>
> So we can say the meteor is at coordinates 4,3 for the north east one and
> -4,3 for the south east one. (And 4,-3 would put it in the north west
> quadrant and -4,-3 would put it in the south west quadrant.)
>
> All that does is tell the robot how the meteor's location relates to the
> zero point set at the landing zone.
>
> Of course nonmathies would say why not just stick with north, south, east
> and west. ;-) For *that* example with the robot sitting at the landing
site
> the north-south reference is probably easier to understand than x-y
> coordinates and therefore better. *But* if you start needing to know
> something about -- relate -- the distance between two meteors rather than
> between one meteor and the zero point, or relate the distance between
where
> the robot is and where it wants to go, or relate how far the robot who has
> moved from the landing zone is from each meteor to figure out the closest
> meteor, then the positive and negative numbers make the calculation
> incredibly easy.
>
> Joyce
>