Thursday, October 29, 2015

Reducing Fractions (using GeoGebra)

I made this today just so i would have another example showing that GeoGebra can be used outside of geometry. My hope and goal is that teachers (and students) would create a digital notebook of helpful files, and use them. One does not need to create in GeoGebra to be able to use GeoGebra.
The original file is at here.

Monday, October 26, 2015

AMTNYS in Rochester

I will be giving a short presentation on "The Power of GeoGebra" at the AMTNYS conference in Rochester next month. I am gathering a selection of my creations to use as examples. You can see the collection as it grows by clicking here.

Monday, October 19, 2015

If the diagonals of a quadrilateral are...(under construction!)

This includes 3 diagonal properties, but the perpendicular setting seems to be in need of some TLC.
Bear with me.

Sunday, October 18, 2015

If the diagonals of a quadrilateral are.. (part 3)

Last Friday I posted two GeoGebra files dealing with quadrilateral displays with congruent diagonals, and with diagonals that bisect each other.
In the attempt to make these one step closer to teacher-friendliness, I have combined them into one fairly self-explanatory file.

This should be added to in the near future.

The actual file can be found at http://tube.geogebra.org/m/1844613

Have fun.

Friday, October 16, 2015

If the diagonals of a quadrilateral...(Part 2)

In my classroom days, I spent a lot of time dealing with students on the diagonal properties of quadrilaterals and what they said about the quadrilateral. I wish I had dynamic geometry software back then.  
Far too often my students would see or hear the word "quadrilateral" and immediately picture a familiar 4-sided figure, such as a rectangle or square. Getting them to think outside of their comfort zone was not easy. Sketches such as these two would have greatly helped. (The 2nd one was posted here first on October 13)

Wednesday, October 14, 2015

How early can they do it?

While delving into Geogebra I feel somewhat obligated to give Desmos its fair chance. I decided today to just plot a triangle with movable vertices.
I did achieve that goal, although I doubt I could get a 3rd grader to follow along, I suspect the third grader could do it in GeoGebra.

I am looking for advice as to a user-friendly means of labeling the vertices. Such labeling occurs automatically in GeoGebra.

Tuesday, October 13, 2015

If the diagonals of a quadrilateral....

Question #1 from the August 2015 Geometry (Common Core) Regents Examination got me to thinking of some of the issues that arose in class back in my teaching days. This is step 1 in a creation that I hope will encompass all the key properties of a quadrilateral's diagonals, each phrased in the "If the diagonals of a quadrilateral are __________" style. Wish me luck!

Tuesday, October 6, 2015

The SSA problem: an aid for teachers

At some point tjis year every geometry teacher in the country will be confronted with the infamous SSA (side-side-angle) problem. I hope this helps.
Available online at http://tube.geogebra.org/m/1771489

Monday, October 5, 2015

GeoGebra or Desmos?

Here is my 3-leafed rose plot in Desmos. Below you will find the same plot in Geogebra. The GeoGebra version, to me, can be presented to students earlier in their math program.

GeoGebra and Desmos side-by-side

Yesterday I was experimenting and came up with a page that places Desmos and GeoGebra side  by side. My screen resolution is 1920 by 1080. I hope and plan to experiment with other sizes.

This experiment is just a stage in my quest of packaging lessons that involve both piece of software in an internal dynamic manner. I do not suppose I will ever get them communicating with each other, but at least I can set it up so that the teacher (or student) has a seamless way of using both in the same lesson.

Thursday, October 1, 2015

Desmos vs GeoGebra?

Here is the best way I have discovered to plot a movable segment in Desmos. Take note that in order to create it I had to have prior knowledge of Cartesian coordinates and parameters. See below for more.

Here I have a version in GeoGebra where I have utilized the limitation of tools available to the student to just "plot a point" and "plot a segment". It is very simple. Make your own right here and now!

In my humble opinion, I could teach a lot of Geometry, starting with the simplest of notions, in GeoGebra, such that beginning students can "latch on" right away. This "latching on" would not be so quick in Desmos.

However, both pieces of software would be used in my classes!