Happy New Year

Or should we say – Happy New Prime Number Year.

As it turns out 2011 has some interesting properties. First of all 2011 is a prime number. But even more, 2011 is a sum of 11 consecutive prime numbers from 157 to 211 and 2011 is also a sum of 3 other consecutive prime numbers 661, 673 and 677.

Have a successful and joyful Prime Number Year!

Source: https://twitter.com/#!/standupmaths

Paul Erdős’ biography

A while ago I found an inspiring video on mathematician’s Paul Erdős’ biography, which I would truly recommend to see.

Video: Biography of Paul Erdős by Paul Hoffman.

In short – he was a mathematician who traveled around the world chasing interesting mathematical problems and moved to his next destination as soon as his fellow colleagues didn’t have any other more exciting problems to offer. He was looking for elegance in mathematics and his life consisted of interesting problems and beautiful solutions. But saying this does not say the main thing – he was an amazing person: with extraordinary thoughts and ideas that surprises and makes the audience to laugh.

Here are some expressions Erdős used:

• Children were referred to as “epsilons” (because in mathematics, particularly calculus, an arbitrarily small positive quantity is commonly denoted by that Greek letter (ε));
• Women were “bosses”;
• Men were “slaves”;
• People who stopped doing math had “died”;
• People who physically died had “left”;
• Alcoholic drinks were “poison”;
• Music was “noise”;
• People who had married were “captured”;
• People who had divorced were “liberated”;
• To give a mathematical lecture was “to preach” and
• To give an oral exam to a student was “to torture” him/her.

More about  Erdős’ biography and vocabulary can be found in Wikipedia.

The lecture available above is really interesting and definitely worth the time.

Questions that make a difference

Wednesday morning turned out to be gray and rainy. That’s why, while drinking my morning cup of tea I was thinking about communication – how do we communicate and how do students communicate with us.

No, no – I am not trying to give the best solution ever or a general recipe for every single situation. I am just speaking about one small part of it.

Let’s have a look at one example: Let us imagine that you are an employee in a private company and your task is to make a deal with a client. And it might happen that for some reasons you are unable to do it. And it might even happen that you decide to go to your boss and complain. At that point you have a choice: you could either say: “I can’t do it, it is too much, I have that and this and that…”. You might even be polite and not scream but the message would still be the same – you can’t do it. Or you could go to your boss and say something like: “In order to sign the contract with the client, I need …. (someone to take care of the other clients, more money, more persons helping, the colleagues to complete their parts or …).

And although the situation has not changed, I bet your boss would appreciate the second approach. There are many reasons for that, but the obvious one is: You have done the work. You have made the effort to come up with an idea how to make things happen.

How does that compare to school? Which approach from your students do you prefer? Students rising their hand (or coming to see you in your free time) and saying in an angry voice: “I don’t get it,” or those saying: “Could you please explain that and that thing again”.

And I as a teacher don’t mind explaining things 3, 4 and 5 times if necessary, but whenever I hear – “I don’t get it. All of it.” it makes me realize that student is not even making the effort to understand which parts they don’t understand. And then I am doing this part of the work for them, but “The one who does the work, is the one who learns”.

Kind of easy and simple in general, but would make such a difference.

Marshmallow challenge

It is always a challenge to figure out something interesting and at the same time useful enough to do on the first day of school. At least it is a challenge for a second year math teacher as I am.

Our first day of school was on th 18th of August and just before that I remembered about Marshmallow challenge from TED by Tom Wujec:

Vodpod videos no longer available.

Link to this video: ted.com – Tom Wujec: Build a tower, build a team

That seamed like as perfect first day team building challenge for my high school students as I was looking for.

So… I had nine groups of two, three or four people participating (depending on class size) and six out of nine groups built a standing structure. The highest structure was 68 cm and the lowest 38 cm.

Here are some photos of the buildings students created:

This team decided to build a lower tower just because other team’s tower looked like it would fall apart soon 🙂

This team’s tower started to lean to the left, so in the last few minutes they managed to create a weird support 🙂

One of the highest structures built.

And again – team builds a low and stable tower 🙂

Have you ever done the marshmallow challenge with your students? Or do you have your own – perfect – first day – math activity for high school students? I would be happy to hear about that.

If you are interested in organizing marshmallow challenge in your classroom, you can find some useful tips and list of all the necessary materials click here: Instructions – Running a Marshmallow challenge is easy.