A math operation table for kids

I had such a thing in Greece when I was a kid. By pulling the i-th and j-th band on a plastic board their product was being revealed. That's how I had learned the multiplication table very quickly.

I wanted to buy something like this for my little one, but I couldn't find anything similar. All math tables work now with buttons. So I decided to construct one by myself.

At first I designed it with xfig: the prototype is table and the full elements are board and leisten. Then I printed them on 300gr carton and cut them accordingly; the board:

and the bands:

which were also cut into 20 elements:

Then I put it all toghether:

1. bottom carton
2. temlate carton, where I wrote the numbers but after putting it inside
3. horizontal bands
4. vertical bands
5. cover carton with 100 quadratic holes
6. stickers (s. below)

I fixed the band sliding by attaching small white stickers on the boundary between the bands (width = 1.4mm). On the right hand side, I fixed paper pieces with paper glue on the front side and post-it glue on the back side, so that I can pull them off and change the number board inside the construction (e.g. this one is for addition, I can change the template inside for sutraction or multiplication). Here the board with all squares closed:

Here with all bands open:

And here some operations:

Tutorium at the TU

Now that I see again my solution in the previous post, I realise the ratio of my work to the payment at that time much better. In Summer term 2009 I was working for this Tutorium:

 4h teaching + 2h consultation + 2h solving the exercises of the home work + 4h correction of the students' home work + 2h preparation of the tutorium exercises + 4h writing/uploading extra stuff (s. previous post) Sum = 18h per week

+ 2h as invigilator during the exams + 6h correction of the exams at the end.

And the only hours that were paid, were the teaching hours.

Ok, I did it for one term. And at the end I received a very good evaluation from the students. And after the exams, some students sent me an email, thanking me for my work as a tutor.

Now, what would you expect from the university administration, if you had such a member of the teaching stuff? Life showed, that the only thing that I had to expect as a scientist, was a job for the next term like the previous one: that is, working for 18h and getting paid for 4h.

I made up my mind considering the following: If you want to be respected, then first of all you have to respect yourself. This was the first and last term working for the TU.