I found a great way to practice point-slope form with my students from Math = Love. I made several mistakes with my first class but learned and corrected for my later classes.
Mistake #1 - Not allowing enough time
We had only talked about point-slope form for the first time the day before and when I introduced the activity I only allowed them about 20 minutes to complete. I had planned to go over Standard Form (see here why I did Standard Form last) after the activity. That did not work as it took about 12 minutes for me to try to explain and go through one example as a class which only left very little time for them to actually complete on their own. It created a lot of frustration when the time went off and not many pairs had managed to complete one set. To make matters worse, I didn't get to do Standard Form fully, so students didn't get the benefit of practicing and they also didn't get Standard Form. I had to apologize to them the next day for that.
I decided that practicing was better than rushing to cover Standard Form so I used the remaining of the class to complete the activity. This allowed for students not to feel rushed on something that they were particularly difficult.
Mistake #2 - Using TI-84 instead of Desmos
With my first class I had students use their TI-84 calculators to check that their equations actually went through the two points by graphing and then finding the two points on the table. This made sense to me, however, the it didn't get across the visual that Desmos creates when plotting the two ordered pairs and then seeing the equation go through both points. I thought that because they will use their TI-84 calculator on the state test it would be good to just teach them how to use their calculator. I should know better - thinking about a state test does not necessarily mean it will result in good learning opportunities for students.
It also took more time to check because we still had some confusion on how to get to the table and exactly what it was they were looking for.
I put the TI-84s away and pulled up Desmos on the Smart board. the visual of the line going through the points made something click with several students - that's always a plus. I started out at the board and students as they finished would come up and I would put type it in but that meant I was tied up at the board, I also started to get a line for the board and I have 30 students which meant it was a LONG line. So, I really stretched my comfort zone and had students pull out their phones and go to Desmos themselves. I did have to mention that the only thing I should see on their screen was Desmos as this was the first time I had allowed phones to be on and out in use during my class. I have a pretty great class didn't have issues with the phone. Students just had to show me their phones to prove that their line passed through the points.
Mistake #3 - Making it a competition
I have a giant pair of dice and then small regular dice. I said I would allow the first pair that found the equation in slope-intercept form from two points and show me their calculator would get to use the giant dice. Of course - it went to a pair that usually finishes their work quickly, great work on their end, but discouraged the remaining of the class when they were already frustrated.
I used Class Dojo random button to select the lucky pair were that would get the giant pair of dice. This was much better because everyone in class had a chance of winning. The reason I originally made it a competition was because I wanted to have an incentive for students to complete the activity. I ended up doing a jolly rancher for every set completed, I removed the competition with the rest of the class and instead made it a competition with themselves to see how many they could get done. I gave out a lot of jolly ranchers! I also doubled the jolly ranchers if they checked their work on the Smart Board instead of their phones.