[Photo by Alejandra Mavroski.]
Myrtle called it The article that launched a thousand posts…, and counting comments on this and several other blogs, that may not be too much of an exaggeration. Yet the discussion feels incomplete — I have not been able to put into words all that I want to say. Thus, at the risk of once again revealing my mathematical ignorance, I am going to try another response to Keith Devlin’s multiplication articles.
Let me state up front that I speak as a teacher, not as a mathematician. I am not qualified, nor do I intend, to argue about the implications of Peano’s Axioms. My experience lies primarily in teaching K-10, from elementary arithmetic through basic algebra and geometry. I remember only snippets of my college math classes, back in the days when we worried more about nuclear winter than global warming.
I will start with a few things we can all agree on…
Continue reading What’s Wrong with “Repeated Addition”?
Photo by Complicated.
Princess Kitten is recovering from her cold and getting some energy back. She came to me and said wistfully, “I wish I could do backwards math.”
I looked up from my keyboard. “Backwards math? What do you mean?”
“Umm. It’s kinda hard to explain, but I can show you.”
Continue reading Backwards Math
This post has been revised to incorporate all the suggestions in the comments below, plus many more activities. Please update your bookmarks:
Or continue reading the original article…
Continue reading 7 Things to Do with a Hundred Chart
[Rescued from my old blog.]
Would you like to introduce your students to negative numbers before they study them in pre-algebra? With a whimsical number line, negative numbers are easy for children to understand.
Get a sheet of poster board, and paint a tree with roots — or a boat on the ocean, with water and fish below and bright sky above. Use big brushes and thick poster paint, so you are not tempted to put in too much detail. A thick, permanent marker works well to draw in your number line, with zero at ground (or sea) level and the negative numbers down below.
Continue reading Negative Numbers for Young Students