## Negative numbers? I think not.

GRIN #

**Negative numbers:**Jerry and I got in a fight about this once. We were in the same math class at NCSU and were doing homework together. The question: “What’s bigger, Negative 5 or Negative 10?” Jerry explained it was -5 because it was “less” of nothing and therefore bigger because -10 would be more of nothing. I argued that nothing was nothing and you couldn’t have less than nothing. If that was the case, they shouldn’t call it nothing; they should call it something else. Numbers should start at zero. How would you illustrate negative numbers with apples, for example? Negative numbers are highly suspect and freaky.**Addictive warnings on nose spray and Chap stick**: Seriously, if I’m addicted to breathing and/or moist lips, aren’t there worse things? Don’t pharmaceutical people have bigger fish to fry?

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May 14, 2010 at 1:02 pm

I experienced almost the same thing helping my daughter with her homework yesterday…..and why is it that on the last homework night of the week, her creepy teacher decides to give her 2 double sided pages of homework??!! Well, it was math homework, and I’m certainly no Einstein when it comes to figures and fractions; so we were working on grams to killgram problems; the question if I remember it was: how many kilograms is 3/1000? I drew a complete blonde blank!!! If I’m no smarter than a third grader, I’m dreading how I won’t be any smarter than a fifth grader either! Have a great weekend Chrissy!!!! 🙂

May 14, 2010 at 4:12 pm

It’s humbling, isn’t is??

May 14, 2010 at 6:25 pm

Hey……..careful with the Pharmaceutical comments……remember we also make the Rx’s that folks need!!! :>)

May 14, 2010 at 6:39 pm

Hey, I love pharmaceuticals, you know that! The warnings, not so much.

May 30, 2010 at 12:00 am

Because my students have such a hard time with negative numbers (ie: solve for y in y + 25x = 3x + 7), I started thinking about what the problem was. I would get answers like “y = -28x + 7” or “y = 22x + 7” so it was obvious there was a lack of understanding of negatives.

For my thesis, I began looking into when negative numbers are taught- 7th grade! What?? That’s too late in my opinion. Then I began to look into HOW they are taught- with a number line. But at the very beginning of the first lesson in 7th grade, there is a picture of a boy with a caption above his head reading “I owe my dad $4. I have -$4”

So this idea of owing is tied directly into negatives. So I thought about owing someone some money, paying some back, and figuring out how much more I owed.

If I borrowed $12 and paid you back $7, the problem would look like “-12 + 7” but I would solve the problem, in my head, by counting from 7 to 12. This is not the way we are taught in school. The way we are taught in school is to “find -12 on the number line, count 7 to the right, see what number you land on.” But this isn’t what we do in real life!

Absolute value is the answer. Although “take the difference between the absolute values of the two numbers” is a bit of a mouthful, it is the way to go. This way both numbers, -12 and 7, are treated as real numbers instead of -12 being treated as a number and 7 being treated as a movement. I really think that if we teach kids this way they will begin to see the relationship between positives and negatives and no longer make mistakes when they get to me!

May 30, 2010 at 3:43 pm

That is awesome! That’s why we need teachers like you:)

May 30, 2010 at 3:48 pm

I wish it was stressed early that subtraction is just the same as adding negatives, like you show up there with the circle around the “subtract 5”. My studnts still see that as different from “-5”, even in 11th grade. There’s a break somewhere that should be fixed.

I hate to plug a product, but my ZeroSum ruler helps with negatives. There’s a video on how it works (as well as other videos) on my WordPress page. I plan to make more videos on all topics I teach this summer, since, as you know, teachers have summers to themselves! (lol)

May 30, 2010 at 4:03 pm

You’re making my head hurt.

May 30, 2010 at 6:16 pm

haha, you sound like my students!