My Favorites – Desmos and Geometry

 

 

Desmos.  Yep, maybe a common favorite for many these days.

• I had used Desmos for class demos and even took my handful of Alg. 2 students to the library to play Central Park on the PCs there.  Then last January the school got a couple of carts of chromebooks.  The students got to explore graphing with Desmos – using sliders, restrictions, etc. – and a few of the activities.  They got to actually switch x and y to see the inverse relation.  In calculus we could see the implicit graphs.
• And now this year, I have enjoyed using the activity builder to set up my own activities.  (I even used it for geometry to share some links and ask questions without using the graphing part of Desmos.)  I got to attend in October the ICTM conference with Eli Luberoff for the Saturday main session, workshop, and seminar.  One student in wrote my name on the whiteboard using LOTS of tiny “Desmos.”  Already several of my classes have given 2 thumbs up on the Marbleslides!

I’ll include a favorite geometry quick activity that I learned while teaching in southern Africa in the ’80’s. – NO tech needed!

• Ask for a couple of volunteers to come and stand several feet apart.  Then ask for another volunteer to come and stand the same distance (equidistant) from each of the first 2.  Most will stand between the first 2.  Then ask for another volunteer to come and stand the same distance from each of the first 2.  If a student is quick to volunteer, often he/she hesitates thinking through where to stand.  I sometimes repeat my instruction.  When a place is chosen I ask the class if they agree.  Then I ask for more volunteers one at a time until the whole class is standing.  I ask the question what they just formed (perpendicular bisector).
• 1 volunteer to stand as my starting point.  Then volunteers to stand “an arm’s length away from the original volunteer. (circle)
• Equidistant to 2 intersecting walls  (angle bisector).

These are fairly simple, quick demos and get the kids moving.  I still remember some of students over the years that were my “points.”