Mr. L’s Math

The California Math Council - Southern Section Conference, Palm Springs math conference will be held this year on November 7-8, 2008 at the Palm Springs Convention Center.
As one of the Featured Speakers, I’ll be presenting two sessions, one on Friday and one on Saturday. These sessions cover two of the topics I’m currently focused on [...]

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The June 2008 issue of the California Math Council ComMuniCator journal has posed the following problem in the student problem section:
“Use each of the numbers 3, 4, 5, 6, and 7, and any operations to express as many counting numbers as possible, beginning with 1.  All five of the numbers must be used in each [...]

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The June 2008 issue of the California Math Council ComMuniCator has posed the following problem in the student problem section:
“What four positive integers have a sum that is equal to their product?  Meaning: a+b+c+d = a•b•c•d.” And if you can find a, b, c, d, then see if you can find five such positive integers.
This [...]

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Kakuro is a number puzzle that is gaining popularity recently, and in some parts of the world it is more popular than Sudoku. Let’s take a look at this phenomenon, see why people like it so much, and how you can use it in the classroom.
First of all, let’s compare it with its fellow [...]

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[N.B. - This post is written by my coauthor from Teacher to Teacher Press, Brad Fulton, with some slight tweaking from me. The activity will work well for students from grades 6 - Algebra 2. This is an extension of the activity Hundreds Magic, which can be found at the end of this activity under [...]

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Pi is probably the most well-known mathematical constant, and it even has its own special day - March 14 (3.14)! Throughout the world people recognize the significance of pi and its contribution to mathematics in particular and to humanity as a whole.
Each year my students celebrate Pi in several ways. We, of course, have a [...]

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Graphic from Wikimedia Commons, a repository of media licensed under the GNU Free Documentation License.
Every year I ask students to memorize 30 decimal digits of pi. When people ask why, I offer several reasons based on improving student performance and ability. Here are some thoughts on the subject.
It helps students focus on a single task [...]

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After students become familiar with pentominoes, they are ready to use them to explore some algebra. Teachers may present this activity either using the white board, or preferably, with the overhead projector and some pre-made transparent pentominoes (colored for easy location) when projected. Using a transparency grid (half-inch or one centimeter grids work well) [...]

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Pentominoes are wonderful creatures. They are fun to create, they can be colored by students, and there are a multitude of questions that can be posed, and many activities to pursue to stimulate and strengthen students’ minds.
This activity asks students to use a single pentomino to tessellate the plane. In other words, can you [...]

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Yesterday’s post talked about polyominoes; pentominoes, using 5 squares, are the polyomino that has gotten the most popularity due to their versatility in generating puzzles. Martin Gardner popularized them in 1957 in his math column in Scientific American magazine.
Pentomino puzzle pieces are simple to make; using card stock (or an old manila folder), create pentomino [...]

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