Well, if you are dealing with objects (say fruit), then it is hard to take away a bigger number from a smaller number. If I have five apples and take away seven apples, what do I have? I guess I could have two anti-apples, but antimatter apples are difficult to find and even more difficult to keep. Of course these negative fruit story problems really get difficult with adding negative numbers.
If Jimmy has an apple and adds a negative apple, how many apples does Jimmy have. Answer: The answer is moot as Jimmy has been vaporized.
If Jimmy has an apple and adds a negative apple, how many apples does Jimmy have. Answer: The answer is moot as Jimmy has been vaporized.
Only if there's been a failure of the apple anitmatter containment field. Or a warp core breach.
Oh, I know - tell the kids that since negative numbers aren't "real," they are the devil's work, and using them will get you sent to hell.
(I'm not using "real" in the mathematical sense.)
For all that is good and holy, why can't the DC DMV get their freakin' act together?
Yesterday I had to go and get a duplicate registration for one vehicle that was never mailed out back in February (and the client JUST let us know), and now I get a phone call that sends me back to the soul-sucking place. Someone dropped the ball and I have to clean up their mess--renew 3 registrations and get a duplicate for another. This is not a productive use of my time people.
If I come back wearing leather pants, someone promise to stake me....
Do ya think Rove got Uncle Phillip headslapped by Dubya?
How would you explain, as simply as possible, to these children why their teacher is apparently lying to them?
I have thought much on this, because I was the one in the class saying, Yeah but --. Here is my answer:
Too much math at one time will make your head spin. We make you learn it in steps to avoid head-spinning, the same way that you can play touch football and then graduate to helmets and pads and tackling when you're ready. Touch football is a perfectly fun game to play, and it works as a game, but there are things you're just not allowed to do. Next year, when you've mastered all the skills touch football can give you, you'll be allowed to try on the helmet and the hard questions like "what are negative bananas?"*
Be patient, play the game we're asking you to play, and when you've practiced enough, we'll extend the rules.
(*) I had a very long conversation, at about age 11, on the subject of subtracting 5 bananas from 3 bananas, and I really had trouble with counting around the number zero. We talked about negative bananas for, like, hours. I am no good at counting to this day.
Instead of telling them it can't be done, how 'bout telling them, "We're just not going to do that now."
Oh, I'm not doing it (as I have chosen the dubious pleasures of adolescents over those of small children) -- this is what, in my theoretical lesson, would be a test question (or a discussion question, I'm not sure yet). That is to say, the 9th graders would have to think of a way to explain it to first graders. The elementary school teachers are on their own.
Do ya think Rove got Uncle Phillip headslapped by Dubya?
Dubya probably needs to consult with Rove about the Rove situation, so it really comes down to whether Rove is a masochist.
Also: I agree, that's totally the way to do it. Although... part of the point of my theoretical lesson plan involves the fact that those teachers aren't actually lying. What they're saying is true for that system. But it would be better, especially if you have students who already know (often from the incontrovertible supreme authority of their parents, siblings, or Books) that you can so do that, would be to explain about the systems. I don't know much about elementary education, so I'm not sure what the best way to go about it would be, but pretty much any explanation is better than "no you can't."
