Sunday, November 9, 2008

Perfect squares

Does anyone out here have ideas about how to set up a nice visual activity to teach middle school kids square numbers (perfect squares)?

Also, any challenging problems are welcome, e-mail me your instructions! I am very fond of logical thinking that doesn't involve much calculations. The kids are always delighted to find the answer by looking at the problem from a different angle, drawing a picture or just arranging the data in a way that makes the questions simple.


In unrelated news, several students told me that I had lost weight. I wonder how it's even possible, given the quantities I've been eating over the past two weeks. Well, miracles are at your doorstep, as it were.

Wednesday, October 29, 2008

Second semester officially open

For the first day of the second semester, I have decided to go easy on the dormant minds of the students. I bet they're more sleepy than dormant, since I can see an unexpected vivacity in their eyes. We start off by a reflection on the previous term. What did they enjoy? What would they like to see improved? What was difficult?

I don't know about you but I always thought that there's nothing like a good problem to hook you up to the matter. I selected this one for my grade seven monsters:

One night, Mint, Nett, Kate, Rakjang and Mai were having a sleep over at Mint’s place.

Mint couldn’t sleep so she went down to the kitchen, where she found a bowl full of mangoes. She ate 1/6 of the mangoes and went back to sleep.

Later that same night, Nett was hungry so she took 1/5 of the remaining mangoes.

Still later, Kate awoke, went down to the kitchen and ate 1/4 of the mangoes Nett had left.

Even later, Rakjang ate 1/3 of what was then left.

In the morning, Mai ate 1/2 of the remaining mangoes for breakfast, leaving only 3 mangoes for the dog.

How many mangoes were originally in the bowl?

And a little bit more challenging:

Three sailors were marooned on a deserted island that was also inhabited by a band of monkeys. The sailors worked all day to collect coconuts but they were too tired to count them so they agreed to divide them equally the next morning.

During the night, one sailor woke up and decided to get his share. He found that he could make three equal piles, with one coconut left over, which he threw to the monkeys. Thereupon, he had his own share and left the remainder in a single pile.

Later that night, the second sailor awoke and, likewise, decided to get his share of the coconuts. He also was able to make three equal piles, with one coconut left over, which he threw to the monkeys.

Somewhat later, the third sailor awoke and did exactly the same thing with the remaining coconuts.

In the morning, all three sailors noticed that the pile was considerably smaller but each thought that he knew why and said nothing. When they then divided the remaining coconuts equally, each sailor received seven and one was left over, which they threw to the monkeys.

How many coconuts were in the original pile?

I expect good cooperation work in this class, that may result in a variety of approaches.

Thursday, October 9, 2008

Officially on holidays

## reception starting, please brace yourself for the news ##

People of mathsland,

I am here to officially disclose a piece of information of the utmost importance: *M* has finished her planning for the second semester and is on her way to some jungly island.

Biip biip, ## end of reception ##

Wednesday, September 17, 2008

End of semester ramblings

*M* is about to turn into an exam invigilator. Beware, beware, for her eye is sharper than the sword.

Good luck everyone, I know you can all make it.

Monday, September 15, 2008

Good intentions for the semester to to learn from my mistakes and move on

- ***Planning

Take advantage of October to do all the planning for next semester. Brainstorm creative teaching ideas, such as cooperative work, cross-curricular activities, games and interactive review sessions well in advance.

- ***Checking

Organise paper-checking into Excel spreadsheets to facilitate formative assessment. Refine the marking system and communicate it to the kids in a constructive way.

- ***Time optimization

Make better use of my school time to benefit from my colleague’s advice, as opposed to getting fits at home while writing worksheets.

- ***Classroom management

…Be tougher on grade 8 students who have been walking all over me at some point. I don’t want to get nasty but I’ll have to adopt a harder line with them.

Now, let's get on with this exam preparation. Off we go :)

Wednesday, September 10, 2008

Thursday's fun - News from Mathslands

*** This is awfully exciting. I haven't poked my nose into a book about particles physics for quite some time, but the last LHC experiment made history and brought me back on the scientific track. Here is something you might want to read: Special report by the New Scientist.

*** Thailand's political roller-coaster is taking twists and turns these days. Our dearest PM got temporarily sacked for appearing in two cooking shows on Thai TV and getting paid for it - mind you. I never expected Thai politics to be nearly as entertaining as French politics but they got me on that one.

Tuesday, September 9, 2008

Wednesday's story

With one of my grade 7 classes, we were discussing powers of 10, and we had built a whole scale, from ten up to one million, using decimal and exponential notation. When we reached the point where they had to express 1 in exponential notation, most of the students were perplexed. I guided them through the process of inferring from the sequence of previous exponents what the next exponent should logically be and managed to elicit 100. It gave them food for thought because they have probably been warned time and time again against the uncanny properties of zero and most of them had rather not fret with that moody animal too much. Some did venture out and stripped this surprising 0 up there, changing the base, scratching their little heads until the substance emerged. Whatever base they tried, raising it to the power 0 gave 1! And A. went timidly, in his characteristic manner: ’Teacher, what about infinity? Does infinity raised to the power 0 equal 1 as well?’

This was one of the best questions I’ve had over the past few months. This kid, A., is passionate about big numbers and the concept of infinity just blows his mind. I caught him writing the symbol for infinity all over his notebooks. Some can’t live without mangas, others feel for infinity…each to their own!

Monday, September 8, 2008

Tuesday's tip

Dear mysterious visitors,

Over the coming weeks, I am on a mission to teach grade 9 students how to manipulate Linear inequalities in one variable. None of the textbooks I normally refer to for good ideas and strategies are very eloquent on the subject so I thought I would ask the maths blogging community for some help.
I was thinking of setting up some activities for the students to get a feel of what inequalities are all about and why the rules we learn apply to this and that case but I don't really know where to start.

I've searched the internet, without much success so far. However, I've come across this on

"The way I like to do this is to give students inequalities and then have them check 10 to 15 points. I then have them plot the true points in one color and the false in another. Eventually the students will begin to see the pattern. This is a very good activity to be done in cooperative groups. It can also be done by giving the students a range and asking them to find 5 true and 5 false points. This gives the students more sense of ownership in the problem and can lead to them developing their own way to solve the problem."

What do you think about this approach? Have you ever tried it out with your kids?
Your suggestions would be much appreciated.

Have a lovely day,


Sunday, September 7, 2008

First ramblings

Welcome to my brand new blog! I am not a newcomer to the blogging scene but I've decided to go more professional and discuss my life and moods as a maths teacher. I have embraced the teaching profession a few months ago and I am looking at ways to improve myself, share tips and geeky jokes with colleagues, or whatever comes up.

I am happy to have you on board, mysterious visitors. Feel free to comment, go wild and have fun.

Mathematically yours,