Day 18: Surface Area of Prisms and Pyramids

Today started our unit on solids. I started by doing Andrew Stadel’s File Cabinet 3-Act task. It was a great way to introduce the concept of concept area. I had students take 10 minutes to try to work out the answer and then had students talk with a random partner (had the students line up in order by the last two digits of their phone number and paired with the person next to them). After another 5 (really 10) minutes, those pairs had to give me one number that they thought was correct. I wrote all their guesses on the board and we talked through a couple of the class’s strategies. I gave another few minutes to let the pairs change some answers now that they’ve heard the discussion. Then, we watched the first part of the answer, until Mr. Stadel had finished one side. Once again, I gave a few minutes for the pairs to adjust any answers if needed. Then, we watched until he had finished four sides (the lateral area as we would come to define). The handles were a big focus point for the class – after seeing what he did with the handles, I gave students another few minutes to adjust their answers until we were ready for the big reveal. I now had 4 correct answers on the board and 4 others that were slightly off, but all were closer than what was given in the first round. The last post-it was great – students were excited to find out what it was and it gave a great tie-in to finding surface area.

Students then did a lot of practice in finding surface areas of prisms and pyramids. We get into surface area of spheres tomorrow, along with volume, and I’m hoping to be able to do Elissa Miller’s Tin Man Surface Area Project. I’m hoping to be able to get a few more cardboard objects before Monday, which is when I predict we will be able to start it. I’m so excited to try it!

Mes étudiants aiment bien le suspense d’une tâche mathématique.

Day 17: Area Projects and Geometric Probability

Today was very free-form. They took a quiz at the beginning, learned about geometric probability, and then had free time to work for almost two hours. During that time, I expected them to work on one of the two projects I gave and/or study for their test, which will be at the start of the day tomorrow. The two projects are attached below and involve finding the area of a lawn to be fertilized and the area of a house to be painted. I like the house painting one better because it asks some more higher-level thinking questions (but not that high-level) at the end, but many of my students have done it before if they are taking my class for grade replacement so I decided to find another one.

A note about geometric probability – I find this topic so interesting! I guess I wished I taught more about probability and statistics, but I haven’t been able to yet. It’s a short section in this unit and I don’t really have time to go deeper into it, but I had the idea today that I should bring in a dart board and actually calculate out the geometric probability of landing in certain places. It would make it much more real, but I just have to find a dart board. Good thing I have another whole year before I might be teaching it again…


Je me suis rendue compte de la folie de mes étudiants quand je les donne le temps libre, mais c’est la folie productive.

Day 16: Wheel of Theodorus and More Area

The Wheels of Theodorus turned out great! I actually only had about half that turned them in today all complete. The other half asked for more time to make their wheels more artsy and creative. I couldn’t say no to that! I’ve realized that I maybe needed to walk the class through drawing the first few triangles so that they saw the whole point of the 1-unit and the direction it has to go, especially with the overlap. Some were thoroughly confused, but I am still seeing good products in the end. I have the pictures of the ones that were turned in and will add more tomorrow when I get the rest.

The rest of the day was pretty boring. Go over new vocab about regular polygons and circles, practice with some examples, more challenging practice, class discussion, blah blah blah. I am missing my word wall, but in the short time span that my students have with the vocab, I’m not sure it would be all that useful. Tomorrow we will do another area project before taking our unit test.

La créativité dans les maths est vraiment source de joie pour moi.

Day 15: Area and the Pythagorean Theorem

So we are now on second semester! The final exams were pretty good. Second semester actually has no proofs, but I don’t mention that to the kids.

As it is second semester, I lose a few kids that were only taking the first semester to replace 1st semester’s grade and I gain some new students who are replacing second semester’s grade. Because of this, I wanted a good group activity to get the new students acclimated. I saw Sarah’s post on the game “31-derful” and decided to try this out. I loved it and was amazed at how the kids were actually all engaged in solving it with their group for the entire time. It took most groups around 30 minutes to complete and the last group finished in 45 after listening to some strategies that were shared. About 20 minutes in, I had one student from each group come into a huddle with me and we shot off some ideas for getting the rows and columns to work. This definitely gave some groups a push. A few were still doing guess-and-check, but this gave them an idea of how they could work a little more efficiently. I loved that at the end, we had all different sets of 31 and we had groups that used wildly different strategies. Here are some pictures:

Next, we got into our first unit of the new semester – Area. This starts with the formulas for the area of a rectangle, triangle, parallelogram, trapezoid, and rhombus/kite. We talk about where these formulas come from and do a lot of examples. We then get into the Pythagorean Theorem and its converse and some special right triangles. I showed the best video about how knowledge of the Pythagorean Theorem and isosceles triangles makes you sound really smart, even if you have no idea what you’re talking about: Wizard of Oz. I then gave the class the last hour to do the Wheel of Theodorus. I have never done it before, but I saw a coworker’s results when she did it and I just couldn’t pass up the chance. I told them to finish for homework. I’m excited to see how they turn out.

L’annee est au mi-chemin!

Day 13: Final Exam Review

Tomorrow is the Semester 1 Final Exam. We spent all of today reviewing. I had some games and then the last hour was given to them to review on their own using their assessments, supplemental review worksheets I made, and their review packet that I gave and I was there to answer questions.

All files are attached at the bottom of the post. Most winnings were candy (thank you amazon for this and this) and math pride.

I started with Jeopardy to review parallel lines and angle-sum theorems. This is something I made while student teaching and I do it with teams. I printed the slides so that if a group got it incorrect, another group could steal the points. I also added a “daily double” worth 1000 points (because I said it makes sense) to one of the 100 point questions to really throw them for a loop.

Next, I had Last Man Standing to review triangle congruence. This game is class vs. teacher. The class receives the prize of the last man that is left in the grid. I pair students up and then call on the pairs one at a time to pick which man to take out. The class is then responsible for asking the question that is behind that guy. There are some bad prizes (high five, fist bump, homework pass in my class since I don’t grade homework) and some better ones (extra credit, candy, extra break time). The class gets really into it at the end when you only have a few left.

Next, we played Dan Meyer’s Mathketball to review special segments in triangles. I play class vs. teacher. This one has kids asking why we don’t do this every day. I always hype it up by saying I was a starter on the basketball team when I was in high school (which was the same high school as about half of them – and their girl basketball team recently won sectionals). Then when I take my first shot granny-style I point out that I started sophomore year on my 7-girl team. Today, I actually was ahead for a good amount because the kids all insisted on taking the far shot and they could not make it. I have never seen so many scrap paper balls hit the rim of a recycling bin before. But they did end up winning.

Finally, we did a Trail activity to review quadrilaterals. In this version, the answers are somewhere else around the room that the students have to find. Students all write the letter that is next to the answer once they find it, and the teacher can check by seeing if the order is correct regardless of where they started. The teacher really doesn’t need to check if the student got through all 10 questions without repeating. I like this activity because it gets students moving and talking to different students depending on where they end up in the trail.

Trail Activity

Je m’amuse bien en classe quand les étudiants s’amusent!