How I Use It
Geogebra can be used to clarify difficult concepts.
While teaching the distributive property, I wanted a visual representation for my students I knew many of them would not remember a(b+c) = ab + ac. I used an applet called "Geometric Proof of the Distributive property." This program shows the distributive property as the sum of the areas of two rectangles. Sliders allow you to change the length and width of the rectangle. To the right of the rectangle is an explanation of how the length and widths will produce an area that mimics the distributive property. This was of great help, because I am teaching a full inclusion Algebra class and the students struggle sometimes with making connections.
Geogebra can also be used as a tool to develop new ideas.
In previous algebra classes, I have also used Geogebra when working with linear and quadratic equations. By creating sliders for m and b values for a linear equation, students can try out different values to see how a changing slope and y-intercept affects the shape and location of a graph. In Algebra 2, this can be extended to a, b, and c values for a quadratic. It has proven very successful because students can quickly come up with their own ideas about what causes these transformations. They might not always be correct, but we talk through everything as a class to determine which ideas have merit. In this particular lesson, all of the students were able to understand the vertical shift, but the horizontal shifts were giving them trouble. We revisited this lesson after learning to complete the square and the class was able to clear up their own misconceptions. These types of Geogebra activities lead to meaningful classroom talk because everyone has an idea to share.
There are many great activities on the geogebra website. The setup is quick as the applet will load in any web browser. In our computer lab, we sometimes have an issue with Java, but if you click, "load as html applet," it will work. The important thing when working with geogebra is to pick an activity that will work with your students. Some programs are more open-ended than others. If your class is not used to exploring things on their own then allowing them to do so with a computer program like Geogebra will not make much of a difference, and you will end up with a lot of off-task behavior. However, with Geogebra, you can make the lessons as structured as you want. For my classes, I will always include some questions to go along with the program so my students know that they need to produce something.