Some ideas just slap you in the face.
I got slapped this morning as I was flying home from LA to Albuquerque. Those little cocktail napkins they hand out with “beverage service” often give me the urge to write. So this morning, nerdily enough, as I sipped my orange juice at 30,000 feet above the Salton Sea, I worked on figuring out a better way to help students grasp the difference in look between positive and negative slope.
That’s when I got “slapped.”
First, you must realize that I use the three-letter abbreviations of POS and NEG for positive and negative. Do some of you use these as well? I mention this because those abbreviations hold the key. You have to use the first letter of the NEG abbreviation and the last letter of the POS abbreviation.
Let’s start with NEG.
The first letter of NEG is, of course, “N.” But look what I noticed …
Visual Clue for Negative Slope
The trick for POS is a tad more complicated. But I’m hopeful it will work.
Visual Clue for Positive Slope
- So what do you think? Will this work for your students?
If you test it out, please let me know what you find. I’m interested to know. Thanks!
A fly …
Who would think that a mere fly could play a major role in the history of human thought?
But when it comes to the development of Algebra, that’s the story. I’ll explain how this works just a bit later in this blog. But it is all related to what is happening now in algebra classes all around the world.
For it’s spring, that time of year again when we get out the graph paper and the ruler. Kids are working on the Cartesian coordinate plane.
One about I like about the coordinate plane is that there’s an interesting story about how it was discovered, or should I say, invented. [Hard to know the right word for an intellectual Invention like the coordinate plane.]