I thought this was pretty funny. So did my students.

Here’s an image I created — obviously playing off of the Nike logo and slogan. I have this posted on the wall in my classroom. Whenever my students start to become lazy, I just point to this sign.

Click for full-size image.

Here is an excerpt from an Associated Press report that was published in my local newspaper this past Sunday (17 Sept. 2006). Some of the information presented in it raises some questions in my mind. I’ve outlined the key statistics in red.

So from the article here’s a summary of the statistics:

In 2004, the percentage of certain borrowers that “paid a higher-than-typical interest rate on their home mortgages” are:

• 32.4% for blacks
• 20.3% for Hispanics
• 8.7% for whites
• 11.5% (all borrowers)

I’m wondering how such a small percentage of all classes are paying “higher-than-typical” rates. Doesn’t logic tell us that exactly 50% of all borrowers will pay a higher-than-typical rate and the other 50% will pay a lower-than-typical rate? Certainly this would be true if the definition of “typical” in this case was “average” or “mean.” So perhaps, “typical” indicates a range of interest rates. Then, the 11.5% indicates the percentage of all borrowers that had interest rates above that range. But if that is the case, it would be very helpful to know the size of that range. Any thoughts?

I’m thinking of a real number. What is it?

You’ve got 20 yes/no questions at your disposal.

Whenever you are ready, ask.

I tried something new today for a review over the basic probability chapter in my Statistics textbook. I created worksheets that contained approximately 50 exercises from the topics we have been discussing. I then assigned each problem a point value - easier problems were worth one point, harder problems were worth 3 points, and ones in the middle were worth 2 points.

Then I told the students that they had two tasks to complete today. The first was to complete 15 points worth of problems to be turned in and graded. This way, they could choose any combination of problems to solve whose combined point value was at least 15 points. The second task was for them to correctly solve a problem of their choosing and then present that solution to the class. If they chose to solve and present a 3-point problem, then they would earn 3 mythical extra credit points. If they chose to solve and present 1-point problem, they had an easier time at it, but the rewards were less (1 point extra credit).

This seemed to work very well today. The students enjoyed having the ability to choose which problems to solve. They also enjoyed listening to their peers explain solutions and rationale to the exercises.

[The phrase “mythical extra credit points” is one that I saw used by Dan Greene on his blog. As a math teacher, and I’m sure others can attest to this, I know that giving a student 3 or 5 or x extra credit points can mean as much or as little as you want it to. “Mythical” seems so fitting.]

On August 24, I posted an entry about a conversation with Andrew Jones.  That interview is now available to listen to or download at the Nick and Josh Podcast page.

Call 1, made at 4:22 pm while driving home from school.

Mr. B: Hello Mr. Schwartz. This is Mr. B, your daughter Jessica’s Statistics teacher. I’m calling because I’ve been having trouble with the amount of talking that Jessica has been doing in my class. Despite several one-on-one converstations with her about the importance of paying attention and not distracting others, she continues to create a disruption. If this continues, I will simply ask her to leave the class and spend the remainder of it in the principal’s office. If you are able to help the situation any from your end, I would greatly appreciate it.

Mr. Schwartz: Rest assured Mr. B, I will deal with this tonight. You will not have any other problems like this from Jessica.

Mr. B.: (Thinks to himself: Yeah, I’ve heard that before.) Thank you very much.

Call 2, made at 4:26 pm while stuck in traffic on the way home from school.

Mr. B.: Hello Ms. Clark. This is Mr. B, your daughter Markesha’s advisory teacher. I’m calling to let you know that I took Markesha’s cell phone from her today. She thought that she would try to be sneaky by hiding in the corner of my classroom and sending text-messages to her friends. She must have forgotten what I always tell my students: “You are not more sneaky than me. I know what you did, what you are doing, and what you will do.” If you would like to get the phone back for her, you may personally come by and pick it up in the main office at school.

Ms. Clark: Well, Markesha knows that she’s not supposed to use her phone in school. But I’ll speak to her about it again.

Mr. B.: Thank you. Please stress to her the fact that her phone needs to be turned off and put away in her locker while she is at school.

We’ll see if these calls actually make difference in behavior.  Sometimes they do, sometimes they don’t.

Today I discovered and downloaded a new program, Google SketchUp. This program is free and is for drawing all sorts of 3-dimensional figures. The tools are very intuitive and the whole program is easy to use. You can save your work in a 3D file to come back to later, or you can export to a 2D image file (.jpg, .png, .gif, etc.). I wish I had this when I was teaching geometry a few years ago. My handouts and tests would have looked so much better!

Here are a few drawings that I made using SketchUp. All of these were made today, the first day I ever used this program. [Click on each thumbnail for a full-size image.]

Conic section - parabola.

Conic Section - bottom view.

Golden spiral.

Golden spiral in three dimensions.

Home sweet home. Yes, I do have stairs on the front of my house. They just were too tedious to draw.

Here’s a quick (maybe) brainteaser from Elias over at Ramblings of an Australian Teacher.

In the multiplication

P Q R
x 3
——
Q Q Q

each of P, Q and R represents a different digit. The sum of P, Q and R is
(A) 16 (B) 14 (C) 13 (D) 12 (E) 10

Think you know the answer and can give a clear explanation? Then email Elias the solution (and post it in a comment here).

My school is one that operates on a “block” schedule. That is, one that has only four classes per day, each of which meet for one hour and twenty-five minutes. Students will take four classes in the fall semester, and then four different classes in the spring. There are some advantages to this schedule (so I’m told), but from my perspective it is a detriment to mathematics education.

In secondary mathematics, the course of study is very sequential — each class building upon skills and ideas from the previous. But what often happens to students in a block schedule is that they will take a math class during the first semester one year and then not take the next course until second semester of the next year. If you do the math, that is a full twelve months that pass with the student not taking a math course. Therein lies the major fault of block scheduling. So much can be, and usually is, forgotten during that “time off” from math.

Recently, the English department at my school has seen the need for ninth graders to take a full year of English classes. They voiced their concerns to the school leadership team and were able to get 9th grade English converted to a full year course, even though every other class remains a one-semester course. I believe the math department is close to accomplishing the same thing for Algebra 2.

Ever since our school implemented block scheduling several years ago, we have seen a decrease in the number of students enrolling in Calculus. I believe this can be attributed to the fact that students are not receiving a “continuous” mathematics education. Even the administrator in charge of the master schedule, a self-proclaimed math phobic, is beginning to see the benefits that would come with teaching Algebra 2 (if not other courses as well) for a full year.