**File Cabinet has got to be my favorite 3 Act lesson to date**!

I am proud of my newfound passion for 3 Act lessons and the final product for my File Cabinet lesson. However, I am even more proud of:

- My students for their interest, critical thinking, and assistance with Post-Its and filming
- My family, friends, and colleagues who took an interest in the project/lesson
- Fawn Nguyen for using the lesson, providing feedback, and sharing her dynamic results, classroom and students with us
- Dan Meyer for calling me 'Crazy Bananas.' I deserve it.
**I own it proudly**!

Here's the story:

In previous years, a Mr. Stadel Geometry class sounded something like this during the surface area unit, "If we covered this object in wrapping paper, we'd need to figure out the total surface area of the solid so we know how much paper to use. Let's use this formula. Blah, blah, blah!"

Cue the sigh, the yawn, the head tilting back, and eyes closing. The class would use a bland formula to trudge through a static textbook question so that they could arrive at some theoretical answer that meant absolutely nothing to everyone, including me at times.

**Not this year**... Dan Meyer's 3 Act lesson format is here to breathe life into applied math. I was staring at this file cabinet at the back of my room, saw a stack of Post-Its on my desk and thought, how many Post-Its would it take to cover this rectangular son-of-a-prism... and so it began.

Forget wrapping paper, Post-its FTW! |

*before*Act 3) last Monday, posted it to 101qs.com and every day I chipped away at sticking Post-Its for about 40-60 minutes after school. Yes, it was a lot of work, but totally worth it! This math lesson/project instantly became a huge conversation piece in my classroom. Students came in completely intrigued by what was going on in the back of my room. They stared at it. They did weird finger, arm, and eyeball measurements. They walked around it numerous times before I finally said, "Make an estimate. It's free! Write it on the board." My whiteboard at the front of the class had about 30 kids' names on it with their estimates. It was so invigorating to hear them discuss or argue their estimate.

**One student made an estimate within 1 Post-It of the actual result**.

Going beyond estimates, students wanted to help and the only thing I felt comfortable having them do was write numbers on the Post-Its and tape down Post-Its that were sticking out. My students were a

**HUGE HELP!**Thanks guys! Knowing I will post my math videos online, I will not include my students in my videos for what I think are obvious reasons.

The math lesson went extremely well. My students calculated the theoretical answer for homework after we watched Act 1, made estimates, and discussed the necessary information in order to answer the question, "How many Post-Its will cover the file cabinet?" The next day we discussed the differnt ways my students calculated. NONE of them used any formula from the textbook. I love it! Students either:

- Found the total amount of Post-Its on each face and found the total sum or
- Found the sum of the areas of each face and divided it by 9 square inches.

I was impressed by their ingenuity, resourcefulness, and independent thinking process.

**Bottom line**: I didn't help. I didn't force-feed them a formula that means nothing to them. Instead, I allowed them to derive the answer. Little voice in my head says, "Derive the answer or formula on your own!" We also discussed potential problems with the theoretical answer as they walked around the cabinet. Check out Act 3 to get a 'handle' on the potential problem. Here's a hint:

Get a handle on the potential problem. |

I asked my new online math teacher friend Fawn Nguyen if she had done surface area with her Geometry kiddos and I was glad to share File Cabinet - Act 1 with her. Check out Fawn Nguyen's blog here for an exciting read about how her kids responded, their inquisitiveness, ingenuity, and the depth in which Fawn took the lesson. One of my favorite parts was seeing the kids come up to her board and measuring the video display in order to make estimates. They also estimated my height while they were at it... classic! I was flattered and happy that the lesson sparked such a great interest with her and her students. They were so kind to send me a 'thank you' picture. I love it! I shared the story with my class.

Another new online math teacher friend Nathan Kraft simply said, "I'm using this."

I'm glad! I hope you do too! and send me some feedback.

I also sent out the video link to family and friends and got a healthy amount of intriguing responses. My brother, who has great insight regarding the furniture business, was able to eyeball two-thirds of the file cabinet dimensions and had a blast calculating the number of Post-Its. It was fun to go back and forth with him about this. When asking friends what their first question was after watching Act 1, one family friend shared a perspective I wouldn't have thought of in a milion years. Her husband underwent chemotherapy years back and they used Post-Its to count down the days left. They had a pack of Post-Its in the car and counted down each of the 33 days of radiation treatment. This was an extremely touching email as I learned a life-impacting fact, all because of a math video about Post-Its.

As I was busy sticking Post-Its on the cabinet all week, staging the next camera angle, stop motion setup, or editing the video, I was honored to see Dan Meyer's blog post of his weekly Five Favorites - 101Questions [4/28/12]. Yes, Dan is correct that I'm 'Crazy bananas.' I am proud of that title and fully embrace it. I also got this tweet from him:

I don't think I'll be using a Post-It for awhile... and every time I use a Post-It I will think of this math lesson. Enjoy File Cabinet - Act 3.

If you'd like the information for Act 2, email me or post a comment. I'm working on making Act 2 files more accessible or downloadable. Until then, drop me a line!

[

**UPDATE**] Check my 3 Act catalog for Act 2 information and more!

Best,

1131

I love that you had the kids write estimates on the whiteboard, it's fun and motivating for them to see others' guesses too. You can't beat having the real thing in the classroom, so that's our excuse for not accounting for the handles :-) One kid said he liked the cool music in Act 3, another wanted to challenge you to cover the bottom of the cabinet. One kid refers to you as Mr. Shaq.

ReplyDeleteYou're our hero, Mr. Stadel. Keep up the great work, and hurry up with the next 3Act lesson so we can steal it again.

Yes, having the real file cabinet in my class has truly been beneficial for many reasons. This week the kids asked if I'll leave it up for the rest of the year. of course!

DeleteGlad your student liked the music... one of my favorite bands: Foo Fighters. As for the bottom, I'm not too sure that's going to happen unless I really was Shaq!

can i use this as a project im a stuent

DeleteI started my filing cabinet lesson on Friday with two sections of students - one accelerated sixth grade and one eighth grade. Neither section finished (our period just aren't long enough) but it was interesting to see how both worked.

ReplyDeleteThe sixth graders worked very well as we just have been talking about area for the last week (parallelograms, triangles, trapezoids, compound figures) and how area is really just about how many squares fit in a certain space. This three act lesson is a great way to test their understanding. I look forward to wrapping it up on Monday and showing act 3.

I also video-taped the lesson (the first time I've ever done this) and it's amazing how much I've learned from it. I want to tape every lesson I do now - of course, there isn't enough time in the day to watch all of these videos, so I'll have to rethink that.

I do have a question for you. Our school is having an art show this Friday and I thought it would be cool to do another Post-It coverage type of thing (a sequel!). There are large cylindrical supports in the cafeteria where the art show will be held. I'd like to cover one of them in Post-Its. Would it be okay if I do this? I would definitely give credit - your name on the Post-Its or something like that.

Gotta go, my 4 year old is putting me in time out because I've been on the computer too long.

Hi Nathan,

DeleteI'm glad to hear that the lesson has been useful and hope it pays off on Monday. The 5th grade teachers at my school were able to use it, make estimates, and discuss area as well. It's fantastic to hear that File Cabinet is getting some air time.

As for the art show and the cylindrical supports: I'M SUPER pumped to hear how it goes. I appreciate you asking, but totally not necessary... it's not like I own the act of covering things in Post-Its. Please, please, please record it via video and/or photos and send it my way. I'd be totally appreciative if you made it a 3 Act lesson and provided me with the specs of the cylinder and Post-It sizes so I can use it. Good luck, I can't wait!

Best,

Andrew

We finished the file cabinet lesson today. It was amazing to watch the kids get excited as the last few post-its were placed. So much better than me just saying, "The answer is ...". Even I got chills.

ReplyDeleteI ended up giving the dimensions and most kids used this to find the number of square post-its. Looking back, I think it would have been better to leave that information out, and just give them post-its to measure. From that they can get the width, then the height, and hopefully the depth.

As far as methods are concerned, only two groups in four sections found the total area in square inches and then divided by 9. Almost everybody else found the number of post-its on each side (probably the more intuitive way). Some also tried to see how many groups of 48 post-its could fit down the back side...this didn't work out too well in the end. And out of everybody, only one student got exactly the right answer.

I think this activity really worked well with kids in groups as I saw a lot of good discussions/arguments going on. Maybe that's how a lot of these three act lessons should work.

I'll keep you posted on the art show - didn't get approval yet.

Hi Nathan,

DeleteGlad to hear the lesson went well. Man, I wish your art show idea would come to fruition! I wish I had a huge cylinder at school we could cover in Post-Its.

It was great to see the lesson in action. I just stumbled across the 3 Act lessons today and can't wait to give them a try. Thanks for the glimpse!

ReplyDeleteHi Margaret,

DeleteI stumbled into 3 Act lessons a bit ago as well. How fortunate for our students, right?

Keep me updated on how they go!

I love this idea! I am thinking about using this for my Standards based students when we go over surface area. Is there any way for me to get a hold of what you used for Act 2? Thanks!

ReplyDeleteHi Darren,

DeleteI'm glad you like this and would be glad to share. Check out the bar on the right side of my blog where it says 'DOWNLOAD LESSONS.' The link for File Cabinet will provide you with an option to either download the Keynote or PowerPoint file. Let me know if it doesn't work out.

I am so sad that I am just finding your blog now. I would have loved to try this activity with my Geometry students before the year ended. Unfortunately, I won't be teaching Geometry next year. I'll just have to keep reading and see what other ideas you come up with.

ReplyDeleteGreat Blog! Keep it coming!

Hi Simplifying Radicals,

DeleteGlad you would have found it useful, and sorry to hear you won't be doing geometry next year. Maybe you can do it small scale. I'm sure there's some type of algebraic application with constant number of post-its each row. Figure out the total using slope and a linear model? Create a linear model for each face of the cabinet? How many times would the front and side both end at the right edge? I'm sure there's something there!

I have to say, I really like the idea of showing Act 1 at the end of a class, sending them home to simmer on it, then come back to dig in. It really gives time to work out how you would try to solve it, before you get the info. It wouldn't work for every 3 Act problem, but sometimes.

ReplyDeleteYea, talk about a hook! I can just see that. 1 minute left in class, "Hey class, I want to show you something." Bam. Bell rings. I'll have to test that out on a few lessons just for kicks. I'm curious if the student interest will sustain until the next day.

DeleteI love all these 3 act lessons and am trying to use them in my school in the UK. What sort of age groups have you used your 3 Act lessons on?

ReplyDeletekeep up the great work

Dan

Thanks! I am using the 3 Act lessons mainly with 7th and 8th graders. However, I am working with some 6th graders during summer school and introducing them to a few 3 Act lessons. Furthermore, I will be taking on an additional role at my school next year that will allow me to also design 3 Act lessons for elementary grades.

DeleteDoing surface area tomorrow! Thanks for the great idea!

ReplyDeleteMatt

It was awesome! I had some of the same conversations with my students that Fawn had! So much fun! My kids want to do the same activity to my file cabinet :-) We'll have to see about that! If we do, I'll record the video and send it to you! Thanks for the awesome task!

DeleteMatt

Strong work, brother! I'm teaching my students about boxes/prisms tomorrow, and I'm fired about about making this my "anchor" for surface area problems!

ReplyDeleteThanks James. I love that this is an "anchor" activity for you. I know exactly what you mean and feel that it's essential for both teachers and students to have "anchor" lessons and activities that allow for stronger mathematics connections.

DeleteI love this, thanks for sharing. I will use it this year. Your kids might enjoy these after their postit surface area fun http://www.postitartcreator.net/ and http://www.smosh.com/smosh-pit/photos/amazing-8-bit-post-it-note-creations

ReplyDeleteThe link for act 2 isn't working for me. I would love to use this in class. :)

ReplyDeleteAll the goods will be found here:

Deletehttp://www.estimation180.com/filecabinet.html

Just finished surface area and volume with my advanced 6th graders. Today is our last day and I posted the question "estimate how many post-its it will take to cover all four walls, the floor and the ceiling". Once they made their estimates and wrote them on a post-it (of course!), I gave them each a post-it and told them to figure it out using only a post-it as a measuring tool. They are having a blast and coming up with all kinds of creative ways to measure without a standard tool. I've had so much fun doing this kind of activity with these guys! My summer work is to figure out how to make these kinds of rich, engaging tasks manageable with a full class of average or below average students!

ReplyDeleteHi Colleen,

DeleteThanks for sharing. I'm sure it was a blast to witness your kids creatively problem-solve. Enjoy your summer exploring these types of tasks. Let me know what you find/produce.

Every math student needs to have this exact lesson at least once. And my students solved it in the same two different ways yours did.

ReplyDeleteThanks for the push to use this task, amigo.

Delete