In my Transformations unit in geometry, I taught translations first. Then, I moved on to reflections and rotations.

My students learn about transformations in middle school, but they use words like “flip”, “turn”, and “slide”. So if I can relate the academic vocabulary to the words they are used to hearing, the lessons go much quicker. Once I reminded students that a “flip” is a reflection, we were ready to start plotting points. We completed this foldable from my TpT store that gives examples for four common types of reflections. The foldable gives the rules, but I also have my students write “count the distance away from the line” under each flap. I give them a rule, because some students like having it, but really they don’t need them for reflections. I also had to remind them about the equation of a vertical and horizontal line and the line y = x looks like. I guess Algebra 1 was too long ago for some of them.

Then, I used this page as practice. I’m less concerned about running out of pages in their notebooks now, so I’m starting to do many more “practice pages”. I wish I would have done this from the beginning! You can download the practice page.

My rotations pages went so well! First, I had my students complete the vocabulary and notation. Then, we completed the accordion book together. You can find it in my TpT store.

The first example in the accordion book doesn’t use coordinates. I typically use patty paper, but I didn’t buy any this year :( So, I turned the foldable under the document camera instead. It didn’t work as well, but it got the point across. When we moved to the coordinate examples, I told students they could turn their notebooks or follow the rules. I was trying to give them options!

Next, I gave students some graph paper and a table. I saw this page idea from Equation Freak and tweaked it only a little for my students. I had them all draw a quadrilateral in the first quadrant. Then, they were on their own to draw the three rotations and fill in the table. I did not include 360 degree rotations. I feel like it’s redundant. This example was a little easy for my kids, but the bones are there. I may need to tweak it a little bit to make it more appropriate for high school.

The last part of the unit was symmetry and dilations.

A few years ago I started teaching rotations by having students turn the paper the required turn. The curriculum I teach uses any point as a center of rotation, so I needed a method that would work for anything, including on external exams when they don't get tracing paper. We use vector notation or arrows to count how many units up/down and left/right the rotated image is from the center of rotation, and then when the paper is turned back to right, they use the notes they jotted down to plot the new figure. It has worked well over the years, and is very easy to teach! It also reinforces vector notation for when we get to vectors. We use the notation for translations as well.

ReplyDeleteI used to teach rotations by turning your paper! I think it worked well for many kids, but I always got mixed up on which way to turn and ended up getting frustrated with that method. Honestly? I think it's a great method and I just needed to work on it more.

DeleteMy new school doesn't emphasize transformations as much and we don't do vectors at all in geometry. They actually do more with transformations in Physics! I used to teach the vector notation too.

Thanks for bringing this up! I think this is a great method!