Yet another GeoGebra

18 January , 2011

Several versions of GeoGebra are planned launched, and you can try some of them now in their beta stages. I have mentioned GeoGebra(prim) earlier on my Norwegian blog – a scaled down, simplified version intended for primary school use. I also suspect there’s a SMARTboard version in the making (although you can make your own version for the SMARTboard by making points and text much larger!) Yet another version is what will become GeoGebra 5.0 (ok, I know we haven’t reached 4.0 yet, but let’s not get into details…), GeoGebra 3D.

A lot seems familiar at first glance, but a couple of new entries can be seen on the toolbar.
CAS is mentioned in the Norwegian curriculum, and up until now, the only free and rather easy alternative is wxMaxima.


At least two new choices of “mode” has turned up. In the picture above you see the CAS mode. This is a part of GeoGebra that can be used for things like solving equations algebraically and simplifying expressions. I solved a quadratic in the screenshot, and I had no idea about the syntax beforehand. It turned out it was similar to most other CAS’s , for instance, wxMaxima, Texas Instruments-calculators and others.


Not many 3D software systems intended for school use exists to my knowledge. One alternative is Google Sketchup. One option in Google Sketchup is to “drag” areas upward to turn them into prisms. This is also an option in GeoGebra 3D, as you can see in the screenshot.
You can download the test version with 3D and CAS here:


Great cleaneruppers

11 February , 2009

Cleaning up  is great fun! Especially around the house!

OK, maybe not, but let’s at least start with a great attitude! Cleaning the computer might be tedious and slightly risky. To delete or not to delete…

I have tried several cleanup utilities over the years. Up to now I have ended with three finalists, who together manage to sort of most of the things I want to get rid of. I have even managed to clean my overly protected work computer with these tools without any danger having occurred. First off I use CCleaner, found at This freeware utility scans and cleans registry, temp files etc. As well as the regular stuff, recycle bin etc. Then I use revo Uninstaller to uninstall programs that I can’t uninstall with the normal procedures. You can download that at .Finally The Windows installer cleanup utility can help you get rid of bad installs. Download this free utility at . I must also mention (again) the Empty directory remover, mentioned in a post earlier. Great for getting your folder structures in order by deleting folders that just has the desktop.ini file in them, or just a picasa.ini or something like that. Get it for no money at all at . Now, if I only can find something that will clean the rest of my desk… Or even better, grade the pile of exams I have in front me and THEN tidy up. I thought we would have flying cars and mainstream jetpacks by the year 2000, so this is all rather disappointing…

Pedagoguery Software: Poly

21 January , 2009

A great little freeware to show off today! As a mathematics teacher, and frequent user of whiteboards/smartboards, I am always

looking for nice programs or web sites to use interactively. This is one particularily good program that does just one thing, but does it good. It shows you the most common and a lot of the uncommon geometric solids. You can (use your hands on the smartboard to) zoom in and out on the solids, open them up and crunch them back together again. You can print the layout nets for each solid if you want to make your own physical model. For instance, have your students make footballs (I am talking soccer, not the “other sort” of football, where they mostly cheat by using their hands) from pentagons and hexgons. Solids can be shown transparent or…well..solid.

Go download a free version at

Giveaway of the Day – free licensed software daily. Edraw Max 4.3 – Create charts, graphics, diagrams, and maps easily.

6 January , 2009

Giveaway of the Day – free licensed software daily. Edraw Max 4.3 – Create charts, graphics, diagrams, and maps easily..

Giveawayoftheday is a pretty cool site, it gives you one piece of software free every day. Of course, this forces a lot of crappy software to be pushed to the readers, but sometimes, gems are found. Today the product is Edraw 4.3, and it seems to be a very good program for drawing diagrams for simple engineering stuff or marketing or if you just tire of MS clipart galleries. also have a sister site,

Mersenne Prime Search

27 July , 2008

Mersenne Prime Search.

This is somewhat a stayer on the Internet. United we stand in our search for the prime numbers! The mersenne primes, that is, a special subgroup of the prime numbers. With the software from the site linked above you can also participate in the search when your computer is idle…


1 July , 2008

GeoGebra Logo

This computer program has now become extremely popular in Europe. This software package makes it easy to draw geometrical shapes (in 2D) and stretch and turn them around afterwards. That is, it’s a DGS (Dynamic geometry system/software). If you have tried Cabri, you should be no stranger to this.

In addition, you get a function drawing program, were you equally easy can draw most function you will ever need (in 2D). This is all done in the same coordinate system, making it easier to see connections between functions and geometry.

You can also do calculations of many sorts in this software. You can calculate with variables like line segments and function values, and they are (of course) automatically altered and updated when you change your drawing or graphs. You can’t do CAS calculations though.

I have tried a few softwares like this earlier, like Cabri and the newer stuff from Texas Instruments, but nothing comes close to GeoGebra in terms of ease and usability.

You can make dynamic documents and send them off to students. You can use a web version or software version of the program and they are completely identical. You can save stuff as pictures, documents or java applets, and embed them in your website, blog or LMS. What’s not to like?

The software is originally made (I think) as a Ph.D. project in Austria by Markus Hohenwarter. And best of all – it’s completely free and lots of resources exist in all kinds of school levels.

I have held a couple of courses, lectures and workshops around the country, where we have started using this program among others. So far I have been to Molde, Kristiansand S, Oslo, Bergen, Stavanger and Levanger. There’s a bunch of exercises and activities at this site, but the little text there is, is in Norwegian.

I will also give a talk at a conference at NTNU in september where I will talk about a practical pedagogy for GeoGebra. My intentions are to focus on the gap between the teacher and learner, and we go about forcing ourselves to take the learner aspect into our lesson planning.