As some of you know I teach 4 Math 8 classes (using the Desmos Middle School Math curriculum inspired by IM/Open Up) and 1 Math “Elective” with a majority of one of my Math 8 classes mixed with some 7th and 8th graders who are in RSP Math. I’ve previously blogged about how I taught students how to play the card game SET with an amazing activity made by Greta.
I have also used other freely available activities with my elective class such as Mini Golf Marbleslides to review plotting coordinates, Pop Music, Electricity Generation, & E-Cigarettes from the Desmos / New York Times “What’s Going on in this graph?” series, The (Awesome) Coordinate Plane, Polygraph: Points, Polygraph: Shaded Rectangles (fractions), Des-Farm (great activity for Grade 6 on ratios), Balloon Float (happens to be from Grade 7 Unit 2), Click Battle, and Area of Rectangles by Nathan Kraft to name a few.
We’ve also explored some engaging topics using Jenna Laib’s SlowRevealGraphs.com.
I couldn’t resist digging into some of the Math 7 curriculum with mt elective. This blog post is to share about some of the lessons.
Desmos’ Grade 7 Unit 1 launches with an activity called Scaling Machines that is freely available.
Lesson 2 is Scaling Robots. This one is awesome. Students warm up by creating their own robot face by dragging sliders that control height, width, eye distance, and the antenna. Here’s what they came up with:
Then students are given a table with their robot measurements and are asked to create a scaled copy giving a height that is double their robot’s height for the “Copy Robot.” Then it offers some visual feedback so students self-assess how they did. Slick. Students then analyze a table of a student’s work and answers if they made a scaled copy. After they adjust the values to fix it and make a scaled copy. We laughed at a students work that used a scale factor of 1000, making the copy impossible to see, but they could still see the green checkmark positive feedback. Another slick screen is another common Desmos strategy: pick the parameters you want to change to plan how you will fix a scaled copy, and then execute your plan. It was really cool to take snapshots of all of the different solution pathways. Loved it.
Lesson 3 is “Make it Scale.” This lesson inspired me to figure out how to make animated GIFs of the activity. In short, I used Loom to capture a portion of the screen and then I used ezgif.com to take that MP4 and convert it.
The activity starts with an awesome Which One Doesn’t Belong prompt. Then students select a rose, whale, diamond, or bee to sketch a scaled copy of. I like how the color selecter on this next screen then limits the color options to only the colors necessary. At first they sketch it without a grid, and we discuss the strategies they used. Then they are given a grid and of course accuracy increases a bunch.
After that they make a sketch of a trapezoid but get to select their scale factor with a slider. Really cool built-in differentiation. In my 8th grade class I also encourage this differentiation. One example is when students dilate a shape and select the scale factor that suits their level of understanding. If you feel you haven’t mastered it, do a scale factor of 2. If you can handle more, try 1/2 or another fraction. If you want a bigger challenge try 1.5.
I have taught the 7th grade Open Up Curriculum a few years back and it’s cool that they have still included some of the same cool-downs.
In lesson 4 students do Scale Factor Challenges where they get feedback on how to undo a dilation or go in reverse. They also sketch and get feedback on how their sketch scales.
Lesson 5 is Tiles where they again personalize their learning by picking the colors and placement of them on a mosaic that they then scale. The goal of this lesson is for students to see that when you use a scale factor, the area gets multiplied by the scale factor twice, or the scale factor squared.
In lesson 6 students are introduced to scale. One cool part is in the warm-up students calibrate their screen by holding up a ruler to a caterpillar that is 4 centimeters long and adjusting a slider. Nice touch. Students scroll through different small and large shapes and make the connection between scale factor being how many times bigger a shape is than another shape while scale compares a real life measurement to a grid square.
I had a short 30 minute period on Monday so we did Paint, which was recently released and is the first lesson of Unit 2. Be sure to ready the #desmosified Blog series about the thought that was put into beefing up the IM/Open Up lesson.
I did this because the last lesson of Unit 1 was Scaling Buildings and knew I would need a full 80 minute period to get the most out of it. This lesson is really thought out well. I love it. It starts with a scale drawing of the Arc de Triomphe in France that is 50 meters tall. It’s on a grid, and students are asked to find the scale, or the value in meters of one unit. Really great lead up. The illustrations of famous buildings in this activity is amazing. Students were able to give input on ones they knew about and it even motivated me to Google some of them for real photos in real life. Some students are able to guess and check some of the answers because they use a slider to adjust the height of the building after given a scale drawing on the left.
I am thoroughly enjoying digging into the Grade 7 curriculum, the Desmos team has put a lot of thought, effort, and ingenuity into it.