January Update

funny pictures

Are you getting ready for the big snowstorm — or is it balmy and nice where you live? For us, the weatherman is predicting 6 to 10 inches, plus drifting. Sounds like a great night to snuggle down with pizza and a movie, assuming the power doesn’t go out.

Major Blog Changes

January was a month of major and minor changes for Let’s play math! blog. My biggest change was moving my blogroll to a separate page. This move gave me enough room to comment on several of my favorite blogs, and I hope to add more notes over the next few months.

It also freed up space in my sidebar for my new Blog parties for teachers widget. (Scroll down to see it.) I was getting frustrated posting little blurbs every time a new blog carnival came out, only to see the posts become outdated within a week — those announcements were threatening to outnumber my on-topic blog posts. Aargh! Now I can post the latest links where they are easy to find, without diluting my main-column articles.

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How Should We Teach Arithmetic?

Dave Marain of MathNotations is running a poll about how to teach multiplication, but the question has broader application:

How should we teach the arithmetic algorithms
— or should we teach them at all?

Algorithms are step-by-step methods for doing something. In arithmetic, we have standard algorithms for addition, subtraction, multiplication, and long division. Once the student masters the steps for any particular algorithm, he can follow the steps to a correct answer without ever thinking about what the numbers mean.

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Euclid’s Game on a Hundred Chart

Math concepts: subtraction within 100, number patterns, mental math
Number of players: 2 or 3
Equipment: printed hundred chart (also called a hundred board), and highlighter or translucent disks to mark numbers — or use this online hundred chart

Set Up

Place the hundred chart and highlighter where all players can reach them.

How to Play

  • Allow the youngest player choice of moving first or second; in future games, allow the loser of the last game to choose.
  • The first player chooses a number from 1 to 100 and marks that square on the hundred chart.
  • The second player chooses and marks any other number.
  • On each succeeding turn, the player subtracts any two marked numbers to find and mark a difference that has not yet been taken.
  • Play alternates until no more numbers can be marked.

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Quotations XIX: How Do We Learn Math?

He doesn’t learn algebra
in the algebra course;
he learns it in calculus.

I have been catching up on my Bloglines reading [procrastinating blogger at work — I should be going over the MathCounts lesson for Friday’s homeschool co-op class], and found the following quotation at Mathematics under the Microscope [old blog posts are no longer archived].

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That’s Mathematics

Things are still hectic, but at least the phone company guy found the problem and got our “extended DSL” service working. “Extended DSL” is what you get when you live out in the boonies. No guarantees that it will be faster than the ancient modem, but at least it doesn’t tie up the phone line anymore.

And it is a bit faster, so I finally get to enjoy You Tube. If the video doesn’t display properly, you can find it at this link:

Funny Math Problems

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The Game of Algebra

NFL football
Photo by velo_city.

My pre-algebra class hit the topic of equations just as the NFL season moved into the playoffs. The result was this series of class notes called “The Game of Algebra.”

We used the Singapore Math NEM 1 textbook, which is full of example problems and quality exercises. These notes simply introduce or review the main concepts and vocabulary in a less-textbooky way.

I hope you find them useful.

Continue reading The Game of Algebra