How I Teach Direct Variation

I use to teach direct variation by having students take notes, but the past few years I have been using Jon Orr's Water Bottle Flip.

There is an excellent Desmos activity that goes along with it. This year I copied and edited my first Desmos activity which was this one.

I added two slides:

I wanted to emphasize direct variation and ask them deep meanings of graphs. One of the questions I asked was looking at the graph on the bottom, what inferences can you draw?

On September 8, there was the NATM (Nebraska Association of Teachers of Mathematics) Conference. During Lenny VerMass presentation, Smoke and you Croak or Huffing and Puffing to Understand Slope, he had a very interesting task. 

Students had to measure how much air filled their lungs. So we exhaled into a balloon and measured (3) breaths and the circumference of the balloon. Then on a big sheet of paper we had to plot all of our data points for the following graphs and interesting things happened. Try it with your students.

Student Created Kahoot

Kahoot is the first tool that seems universally accepted tech tool in every classroom. I can see why, its fun to play against others. I remember when I was growing up we played a game in middle school called hands down, if you were the first person on the bottom and had the correct answer you scored points, it was my favorite.

But, Kahoot has been placed in a DOK 1 or DOK 2 depth of knowledge when students are playing. It is hard to find Kahoots where students are not only just remembering or applying theorems but creating and evaluating. One of the things I wanted my students to know is how teachers choose Kahoots and for them to not only review but practice and evaluate others Kahoots.

Paper Kahoots

We started in the classroom with paper Kahoots as a lesson. We talked about how long it would take to do the problem, where there answers that were misleading, and what did the student know if they got the question wrong. Here are some examples students made.

You can find a PDF version here:


For students to create their own Kahoots I had to change my username and password, since Google Sign-in wasn't cooperating. Some students took off and were self sufficient other students struggled coming up with questions, because of the content. I had to ask them how to be a teacher and what kind of questions I would ask.

Created Kahoots

Most students took the route of pure vocabulary and no mathematical questions, but I did not specify what type of questions, now I know.

Here were some example questions they came up with:

Artist Sol LeWitt and Points, Lines, Angles

Sol LeWitt was an artist born in Hartford, Connecticut in 1928 he was most known for his conceptual art, however in this overview we are going to focus on his Instructables. Instructables are wall art where the artist has to follow a particular set of instructions. Sol LeWitt came up with a large number of different instructions, some he never did himself.

For example Wall Drawing #65 in colored pencil is of follows:
Lines are not short, not straight, crossing and touching, drawn at random using four colors, uniformly dispersed with maximum density, covering the entire surface of the wall.

This is what Sol LeWitt came up with:

This is bad example, because it does not take in the sheer size of the piece. Since it is a wall piece it is so large that you could not fully see it from one spot.

So how does this relate to math?

Sol LeWitt has hundreds of these instructions were he takes shapes such as squares, circles, and triangles. He also loves lines, some straight some not, and vertical and perpendicular angles. So to introduce and apply the first section of geometry points, lines, and planes. We attempted our own Sol LeWitt.

Our instructions were: On a wall surface, any continuous stretch of wall, using a hard pencil, place fifty points at random. The points should be evenly distributed over the area of the wall. All of the points should be connected by straight lines.

I assigned all students a letter and then had them connect to each other, so we only really had 26 points, but our artwork was just as amazing.

It did take a little bit more time than I was planning, but the picture at the top took 8 days to make.

We talked about lines and line segments and this brought up a good conversation about how we name lines. I would ask a student which one is the longest line, but would not let them get out of their seat. So it was easier for the student to name the line segment than point.

I love using art in the classroom and Sol LeWitt's Instructables are an easy way to get art in the geometry classroom.

Below is a PDF with some Instructions to do you own.