Piecewise Function Success

Every year as I teach piecewise functions in precalculus, there are students who get it and can successfully graph and understand them, but there are too many students that struggle. I've tried various things, but nothing with consistent success. Well. Last week after school I was helping a struggling student, and as I was looking over her old test, I saw that the mistake she seemed to make on the "3 piece" piecewise function was that to graph it, she made a big table with the same x values and used the same x values for all 3 pieces. I started to say what her mistake was, but then it struck me that if she reworked the idea, it could be very useful.

It worked for all the struggling students I had a chance to try it on, so I think this is how I'll start next year, and then show them the "other" way for those that "get it" and don't want to make such a big table.

The Week, The Wiki-stix, & The Web

I went to another workshop this Thursday, and the algebra 1 information was very useful. What was NOT useful was the handful of people sitting at my table blatantly grading huge stacks of tests and totally disregarding the presenter and going so far as to discuss with each other about how to allocate points. Oh my.

What was ALSO not useful was my understanding of just how broken our "mentoring system" for new teachers is. One of our new teachers is TOTALLY struggling and crying and breaking down in class and being overwhelmed. I've heard from her mentor that she went in and gave her tips on what to do (do warmups, here are some activities, ...), and said the girl did not take her advice, and then the mentor thinks that's the end of it. Well, I sat in on the girl's class. Warm Ups are the least of her problem. There are some easy fixes that just need to be addressed and monitored and modeled and reinforced.

Anyway! After many deep breaths, I decompressed with some of my favorite "feel good" websites. Here are 2 examples:
DarynKagan.com (here are some old good ones)
http://darynkagan.com/heroism/stories/he_080324_computerfairygodmother.html
http://darynkagan.com/kids/stories/ki_080414_oneboyandaredwagon.html

smittenkitchen.com (yummy looking recipes) ... for example:
http://smittenkitchen.com/2008/08/chocolate-peanut-butter-cake/

Also, I found yet another use for the wiki stix. We started radians in precal today, and my first question was how many radii did they think fit around a circle. They drew circles and the radius, and then with a small piece of a wiki stix (stick?) they marked out the radius along the circle. It was easy to manipulate and curve.

And the funny joke I read in a book this week:
knock knock
who's there
little old lady
little old lady who
I didn't know you could yodel.

Life's Surprise Pop Quizzes

We are being judged and evaluated all the time, and we may not realize it. In fact sometimes we may think we're getting away with things when really we're not. This past week seemed to be full of those "pop quizzes", and now my outlook on a variety of people has altered.

test1: I gave my first test in precalculus this week. As I walked around the room, I noticed the continuously wandering eye of one boy. I stood near him after that and asked him to keep his knees forward (instead of turned towards a "smart" student). Then he turns in his test early indicating he had troubles with one problem (he left blank). Trying to promote his perseverence, I said, "you're a smart kid, keep looking at it and maybe you can work something out". I realized my mistake once he picked his test off the pile of "done" tests, when he walked back to his desk and I saw him erase another problem's answer immediately and put down what I'm guessing he saw on the pile. Now none of this was provable, so I didn't snatch his test up, but this was the 1st "life quiz" he failed. Even though he thinks he got away with things, I will no longer see him in the same way, and he will forever more be the "cheater" to me.

test2: For the nth and (n+1)st time one of our math teachers was basically bad-mouthing other people. In the first instance she was talking about a new teacher that was struggling, and after she recounted the struggles, she mentioned that this person was ONLY hired because we were desperate, and the new teacher must not have had strong interviews because she was not snatched up by other schools in the district. Her second mouthing incident was about a teacher at another school that our new AP wants to hire. She recounted 2 or 3 bad things about her personality and her teaching ability. I wasn't part of the 1st conversation (came in on the tail end), and for the second, I tried to say something nice about the other teacher, and basically I didn't say anything to this lady. BUT now I think of her as the bad-mouther. I wonder what she may say about me or about other people even though she's nice to me/others to their face.

test3: I park a ways away from the grocery store entrance in order to get some free exercise. I was walking back to my car and it looked like someone else with a cart had the same idea. After she was finished unloading into her trunk, I wondered if she would make the uphill trek to return the cart to the right place or just leave it willy nilly to bang into other cars. I was betting on the latter, but she surprised me and restored a bit of my faith in people by conscientiously walking it back to the "right" place.

test4: I walked my (cute little puppies) algebra 1 9th graders over to get textbooks this past week ... after I discussed hallway behavior and such. I also walked my precal and calculus classes over (older kiddies). When we got to the book room, the "manager" seemed surprised I was trusting the 9th graders with textbooks since apparently they don't have good reputations of caring for them and returning them. He even added an extra spiel that he didn't for my older kids about the cost of the books and such. Well, after they went through the checking out process, he told them all they were the best behaved 9th graders he'd ever seen. And I have to agree since out of my 6 classes, they were the best behaved through the whole process. Go Them!

Math Workshop Already!

During the 2nd week of school I had to get a sub for Friday to attend a 2-day math workshop. Oh my, whine, whine, whine: too early in the school year, too hard to leave students with meaningful work when we just started, sets a bad precedent, .....

Okay. It was a great workshop. I learned so many things that will be BIG payoffs in the long run, so can I take back my whining? (except for the fact that now in 2 weeks time I'm basically mandated to miss another day to go to another workshop).

Here are some things I learned:
* a way one teacher gets her kids to remember the divide by zero and zero divided by something rule: 0/K = 0 means it's "okay to have a zero in the numerator". N/0 = undefined means "NO! you cannot have a zero in the denominator".

* which reminded me of the way I learned a long time ago to help kids remember the no slope and the zero slope of vertical and horizontal lines: "No" starts with a capital "n" and when you're writing "N", the first line is a vertical line, so vertical lines have "no slope". "Zero" starts with a capital "z" and when you're writing "Z", the first line is a horizontal line, so horizontal lines have "zero slope".

* with calculator usage for calculus and showing a function and its derivative function at the same time ..... put one in y1 and one in y2 and in MODE change the graph style to "simultaneous", and then you can start and stop the graphs at will and have a rich discussion about positive and negative slopes and + & - derivative values throughout the whole graph.

* I never remember which one of the "ON" or "ENTER" buttons on the TI=84 stops or pauses the graph, so I always end up pushing both. Well! The "ON" button stops the graph, so you can get "ON" with your life.

* Which reminds me of what I shared in the same session regarding calculators and limits to infinity. I have my kids look at just one of the polynomials of the numerator or the denominator in a rational function, say 4x^3 - 2x^2 + 100. I ask if you plug in larger and larger numbers, will that evaluate to basically the same or different value than if you plugged in the same large number to 4x^3 (the dominant term). They are convinced they'll be different. So we put 4x^3 - 2x^2 + 100 into y1, and in the main window do "function notation" of y1(5) and compare it to 4(5)^3. Then we start comparing the 2 things by typing in larger and larger numbers. They're eventually the "same" on the calculator. I tell them that the highest power term is like the ocean and all the other stuff is like spit, and if you spit in the ocean, it doesn't change the volume much, so you can basically ignore it when you are calculating limits at infinity.

More Games and Such

I decided to add 2 new links to my homework website for games since these are ones I love love love. The first is ABC pureisu. Basically you place the letters A, B, & C (and sometimes D) so that every row and every column has exactly 1 of each. You can click around the buttons to get different sizes and difficulties of puzzles. By clicking in the box, you can place your letter.

The second is a "squiggly" sudoku site. I love the different variations of sudoku, and this one also has different difficulty levels. A different puzzle appears every day. This one you have to print out.

I had put a "notes" section on my website, but ultimately knew I wouldn't keep up the copying of the notes, and I didn't know how helpful it would be. So I decided just to sum up the topics of the day/week and mention what would be important to know how to do, and then I will provide web links to various sites that show/quiz/video/tutor/etc the same topic. That way the students have a different way of learning the same thing, and maybe a different explanation will make things click for them or just let them review more. It also gets them in the habit of searching the Internet using the topic name, and they can find other help.

Testing Scribd

I gave the following quiz today in Algebra 1, and I've had "Scribd" on my radar for some time, and then I saw it used on the "f(t)" blog, so I thought I'd test it out here to see what's what.

http://www.scribd.com/doc/5267432/graphing-points-quiz

Hmmm, not exactly perfect, but I'll work on it.

My Book Love Affair

I have passionate feelings for this resource and turn to it whenever I need great ways to ask questions or great real-life examples. I got my copy at an NCTM workshop, and am doing the happy dance ever since. For example, in precalculus today we were talking about function notation, and after we did some "math" graph and table and equation examples, I pulled 2 context examples from the book. One was a table having to do with NFL revenue for a number of recent years, and one was a velocity vs. time graph for a man going to the store.

They both generated discussion about the amount of money NFL made (billions!) and interpretations of the velocity graph and why it may be so "wiggly" going up and down and such and how you knew when he reached the store. The questions were worded such as: find v(24) and interpret the meaning. So they had to think about what "24" meant in this problem and what the "y" value meant and put it all in a coherent sentence.

We also started a discussion on graphs such as y = abs(f(x)). We first refreshed our memory on abs(x) (much needed for some folks). Then I had them make a table for f(x) = x*x - 2 and graph it. Then I had them hold up their hands in the shape they thought y=abs(f(x)) would be .... some, of course, held up "V" hands. So we made the table values and graphed JUST the points, and then I showed them the visual of "flipping" all the negatives "up". Ooh, ahh. That was a good segue into doing the same table/graph thing with f(x) = x ..... then doing y = abs(f(x)).

On a whiny note, my 6 class sizes so far are: 31, 22, 17, 26, 39, 34.

I'm just saying. .... but maybe that's the norm in other schools. BUT, I rember my math teacher friend in another state complaining that she had LARGE classes one year .... "26".

Wikki Stix & Me

A while back I was first introduced to Wikki Stix at a calculus workshop where the presenter showed how she taught slope fields by having large pieces of graph paper around the room, and each group had a differential equation and each person in the group had a point or 2 or 3, and they were to calculate the slope and stick the piece of wikki stix on that point in the appropriate slope. Super cool.

I was at a teacher supply store the other day, and found 48 for $5.95, and bought them thinking I could find some use for them. Well, now I have 2 things so far. On the first day of school, I will review functions and lead to function notation and how to read f(x) and find f(3) and find x such that f(x) = 6, etc, by first handing out premade graphs/grids/coordinate planes to each student and one wikki stix (stick?) to each kid. I'll first instruct them to plop down a "graph", and maybe have them decide if they're functions or not and maybe have themselves walk with their graphs and separate into 2 camps of functions and non functions. They can then self correct by glancing at others and discussing it amongst themselves. Then I'll say find your f(3), and separate yourselves into like groups (how to deal with non integers .....???). Anyway, you get the idea. I could do more.

My second idea is what I think is an improvement on an old activity I've done with precal in the past regarding learning the sine and cosine graphs. But my teacher friend (who I first learned to teach with/from) in another state basically does the same activity but with Wikki Stix. She has them do the measuring of the angles and the heights, not with a string, but with the Stix. Also, once they measure the "height", they snip the Stix into that length and "stick" it down on their graph. So ultimately, later on you have a Wikki Stix sine curve graph. Way cool and something I'll try this year .... though with 3 precal classes of (current sizes) 37, 32, 30ish, how much will that cost?

New Skills

I was at a math workshop today, and from a participant I learned a great calculator skill that left me saying, "where have you been all my TI-83/4/silver edition/titanium life?".

Suppose you're graphing, and suppose you simultaneously want to see the graph and the table screens. Well: mode > G-T, and poof, when you hit graph, voila, split screen. Then you can toggle between the 2 parts by hitting the "table" or "graph" button, and then you can do whatever you want on that part of the screen.

Also, you can split the screen horizontally (mode > horiz ...) and then you can show the graph and either the main window or the lists or a table, etc.

Ooh, aah.

First Day Back Haiku

Inservice Monday
Meeting, meeting, lunch, meeting
Where did summer go?

Addiction

Ackh! In the process of updating my homework website further, I thought I'd add a "games" link that showed some fun thinking/math/logic games. Well, of course I had to try them out to see what I was linking. .... Too many hours later, I'm addicted to 2 I found at http://www.coolmath-games.com/ : "walls logic" and "bloxorz". The first has you building diagonal walls on each of the tiles in a grid, and you can't form loops, and you have to follow "# of walls rules" for certain intersections. The second has 33 levels, and you basically move a brick around to get it in a hole. ... Okay, must stop playing and go do other things.

On a side note, as I was trying the new games, I found myself getting blurry eyed just reading all the instructions, and I just wanted to jump in and test the waters instead of reading about it. Hmmmm, sounds familiar. So now I'll try to think of each school lesson in a new way: how can the students get started right away doing something and then learning what they need to know about it at various stages of the class.

First Day Algebra Activity

It looks like on 8/25 we're starting right away with 1.5 hour block classes when school starts (as opposed to meeting all classes and having an "alpha" period with about 40 minute classes). I need about 40 minutes to call roll and ask for pronunciation corrections, have them fill out a seating chart (I like them to sit where they want the first time, so I see who can/can't sit together when I soon make a seating chart), take pictures of groups (so I can memorize names), and talk about the syllabus. While all this is going on, I like them to be doing something. Here's my something:

They'll work on it quietly while I'm calling roll, and then I'll prompt them to check and work with their group and meet everyone in the group while I'm snapping pictures. Section "A" prompts them about "PEMDAS". Section "B" has orders-of-operation problems with 2 answers to circle, one for the common mistake and one correct answer. Section "C" has a fraction/decimal/percent table with one column filled out where they fill in the other 2 with equivalent expressions. Section "D" has four "4"s and an answer, and they're to fill in operations to get the right answer.

Here's part of their first assignment (and parent homework):

This is a math autobiography and asks questions about past classes and school experiences and such. It also asks their parents to indicate "I am proud of my child because" ....

This will tell me many things about the student: if they do work on time, if they are neat/verbose/last-minute/thoughtful. They also get to see their parent's bragging comments (and sometimes if there are no comments, I'm sad for the kid). I also have a good opportunity to get their parents' e-mail address for future grade sending.

Then I have about 50 minutes left. I'm thinking of a "box plot" activity and a "meet and greet" activity. ... still in the planning stages, though.

Whew! Two tasks done.

My Summer Vacation

Just last week I went to an aerobatics contest my husband was in. It's small, so EVERYONE is wrangled into volunteering somehow.
I got to be a boundary judge and learn the skills of how to read a sequence card and how to call the ins and outs and how to survive blistering heat and curious cows and carcas sightings. First my partner and I (another wrangled wife) had to drive 10 minutes to the location.


Here is an actual corner boundary that the pilots would see from the air.

This is the other wife sitting in position ready to call outs/ins. The contraption is uber cool and thought up by an engineer/pilot who used a compass and his brains. AND there's math involved (what else).
There are 2 sets of 2 strings lined up perpendicular to the other set, and you line up the strings of one set with your eye and .... since 2 lines form a plane, you can determine when the aerobatic planes cross the boundary or not. We were at the "southeast" boundary, so our job was to call "out south", "in south", "out east", "in east".

Boy were we stressed about doing it right. We're not pilots, and we had to figure out what squiggly lines on the cards matched what things the pilots were doing in the air. Eventually, we mastered it as a team. Here are some things that kept us company each time we went out.

Website Goals

Well, I am glad I started my homework website last year, and I'll continue it this year. I found many benefits:

* I made one of the 1st homework assignments be for parents to look at the site and send me an e-mail. This gave me their address for sending home grades, and it also made them aware.
* It gave me a place to post extra worksheets and solutions where they could download them (I didn't do this too much, but maybe will increase it this year)
* Students had an easy way to find homework assignments for whatever reasons.
* Parents now had a place to see/check whether their children had homework or tests coming up.

This year ... (with my 4 PREPS!) I'll continue it, and I want to enhance it:

* I want to somehow incorporate quick easy-to-make-&-upload videos showing various math techniques (I'll film them).
* I potentially want to link to videos from TeacherTube (since YouTube is blocked at our campus).
* I want to post notes for students that are absent (this one I'm iffy about for a variety of reasons: difficulty, space issues, student accountability, ...)

All in all, I'm happy with weebly.com. Hopefully, it will continue to be free or even cheap, and hopefully they'll resist putting ads on their/my page since that was a big draw for me.

Passive Learning

I picked up the AP Calculus exam scores for my students, and while I had a good number pass, there weren't as many passing as I expected or knew that COULD pass. This made me reflect over the school year and day-to-day activities and behaviors of the students. For the ones that didn't pass (but that could have), I see a pattern. They were seemingly attentive in class. They did their homework. They did reasonably well on tests. However, they did not pass. I think a big key is the "seemingly" attentive in class. They learned to play the game and knew to make the "paying attention" actions, meanwhile, maybe for a large portion of class, their minds were elsewhere. (this also goes for my other, nonAP classes).

I've never consistently had daily assessments at the end of class (of some form or another) to see who's getting it, and who's not. Yes, I've walked around class and they practice the skills. Yes, I know who's struggling. Yes, I suggest they come in for help. BUT. There was no consequence to them whether they followed up or not. My tests were structured in such a way that they could do corrections and earn back some points, and that was enough of a safety net for students.

On the plus side. Many (all?) of my students care about their grades, so I've started thinking. There are 6 weeks in a marking period. On block schedule, that means I see them roughly 15 times. Each day I could have a quick assessment (5 minutes?) at the end of class. Everyone getting a different problem (or at least everyone in one group of 4 getting a different problem) ... or 2 problems ... based on the day's topic. This could be worth 1 test point and so by the end of the 6 weeks, totally, this would add up to approximately 1/2 a "normal" test. They'd get 100% if it's correct. If anything is wrong, they have the option of coming after school to make it up. Each time it takes them to make it up (to 100%), their grade goes down to a B then a C, etc. Their tests are weighted about 75% of their total grade, so this would be significant enough to make a difference.

This way, they'd have more of an incentive to ACTUALLY focus and learn during class time because they'll be held immediately accountable for the information.

Possible "cons":
1. more paperwork (though it's only 1-2 problems per student and maybe I can have a limited # of total problems and put the problems on the overhead so they just have to have paper).

2. Would it have the desired affect? (well, I think so, and won't know until I try it) ... maybe I have to incorporate other things, too.

Differentiating Instruction in High School

I know it's a good idea. I know it's what we're supposed to do. Maybe I'm even doing it sometimes (most times?) and don't even know it. BUT. There's always a part of my brain saying, "too many kids, too little time, not enough resources specifically for math or for high school ...". Everything I have read in the past seems to be, "give projects!" and that seems to be the bulk of what I got from their suggestions.

This book (http://www.amazon.com/Differentiating-High-School-Classroom-Strategies/dp/1412917166/ref=sr_1_1/105-4459711-7881269?ie=UTF8&s=books&qid=1216748751&sr=1-1) seems to be different (from my glance and quick read through at the bookstore and through reading the 1st 5 pages and looking at the bulk of what each topic is about). I like the fact that the woman is (was?) a high school teacher. She has taught not just the "cream of the crop". She's not a PhD researcher who only knows theory. She talks about many obstacles and how to overcome them. She talks about the fact that, yes, we do have lots of things that get in the way. AND. The best part. It's geared to high school. Hopefully, I'll absorb the material and be able to use it as a springboard to make some progress this year on my differentiation.

Cumulative Knowledge

I've been batting an idea around in my head for a while to deal with the following problem. Students in AP Calculus need to remember information from (say) August on when they take their exam in May, and students/people have a very hard time recalling information they haven't seen in months even though it may have been "easy" for them in the past.

I don't want to give cumulative exams because I believe:
1. either the students will just shrug their shoulders and give up those "past" problems for lost points,
2. it seems more punative even though it's for their own good
3. I won't be able to cover ALL old topics every time
4. it would only be a (possible) review for students (say) every 2 weeks or so

So my thought is that I want to assign cumulative homework basically every class, and as we are on a block schedule, I'll give them "2" homework assignments each class, one for new material, and one for old. I don't want to have to scramble for old material every time, and I want it to be accessible to the students, so that the review process is not so painful. Here's my germ of an idea:

Have a designated folder on the computer for cumulative work. Have a pre-mapped idea of what we're learning for the whole year (and its timeline) and how many assignments I roughly need. Each time I teach a new topic, I'll have some notion of how many times I want it to appear for all the documents and I want to spread it out, so that day/week, I'll just take the basic problems (?) and cut and paste them into all the appropriate files with an "answer bank" (in some form) on the bottom of the page. It's fresh in my mind since I just taught it, so I don't have to waste time coming up with new problems for them to review. Also as time goes on, the assignments will either be completely filled with problems, so I'll just touch it up and print it out, or it'll need just a wee bit of extra work. I believe I'll also put the date(s) we learned the topic near the problem, and since they'll date their notes ("hey baby, want to go to the math movie tonight?"), then they'll be able to easily flip back and brush up. Also, since the answers will be there, they'll have immediate feedback if they remember the process correctly or not.

I'm also thinking that at the beginning of the year, it'll be slim pickings on "review" material, so I may assign things like (along with a brief tutorial on the page) finding equations of lines given various information, fraction work, factoring work, ... the basics that seem to need extra gentle and not so gentle revisits every year.

Volume of Revolution Project

This past year I tried something new with my calculus students for the "volumes project" in the oh-my-goodness-what-to-do-after-the-exam phase of the year (closely linked to the eek-I-hate-giving-class-time-to-do-projects-and-can-they-waste-any-more-time phase of teaching calculus).

I did the project with the kids to see what was involved, and I told them it was the first time I'd done this, so we'd learn the pitfalls and tips and such together. I also was vague on how they should display the projects at the end. I said, "wow me" and "whatever you do, have a good reason for it" and "think of the best way to display it to use as a learning tool".

The general idea was that we'd all have the same starting 2-dimensional region (y = 4 - xx), and we'd each revolve it around a different axis of revolution, and thus each have different solids at the end.

She wowed me with her final presentation:
This is mine (I now realize I took the picture upside down). Hmmm, spaghetti/math-tool ... probably not too long lasting:


Before she started, she kept saying, "I want to make it into Saturn", so I guess she continued with her space theme:

He was so funny, "tell me what to do. tell me what to do." Me, "no. no. NO.". He finally came up with it himself:

Hand Holding vs Solid Examples

I feel like a flippy-floppy fish on this whole topic, but I guess I could "spin it" as I'm readjusting my attitude as I gather more data. For the last few days, I've been studying statistics for the N.B. exams I had to take today. I went right to the source and bought a prep book for AP Statistics. Since it's a prep book, they don't TEACH every topic in depth, they just review it and do SOME examples and then give practice tests. ... Maybe not the best way for me to review something I haven't seen in ... oh my ... 16+ years.

I found that as I was learning one of the topics, they kept describing each piece/terminology of it in many ways and then building on and then redescribing each piece/terminology, and I found myself saying: JUST SHOW ME A SOLID EXAMPLE FOR THE LOVE OF GOD. And then I had to laugh and say, "oh what, you want them to HAND HOLD YOU through the stuff? can't you piece it together yourself for the joy of learning?"

"Gripe 2": there were SO many new vocabulary words that I'd understand in the context while I was learning it, and then when the book refered back to such a word, oh say 50 pages later, I was thinking, "yesssssss, that SOUNDS familiar, but holy cow, don't ask me to use it in a sentence other than: _____ is a word related to statistics.

All this to keep circling back to the topic of how my (any) students learn and retain math. I guess mostly I write this, so I can get over my uppity self and keep in mind that learning anything new and hard for students is, well, hard, and students should be provided with scaffolding and good-humored reminders that they're doing something hard and should pat themselves on the back between note-taking and problem doing and such. AND teachers should keep this in mind and keep spiraling back to old topics and bla bla bla.

WooHoo! The School Year is Over

The students' last finals were on Wednesday 6/4/08. We had to come in on Thursday to check out, and our graduation was held in the early afternoon. I went in on Friday to finally clean up the rest of the clutter in my classroom. And now ... I'm at home completely done. Whew. As usual, it sneaks up on you and is over before you know it. (unless you're still in school, and then it NEVER seems to be over)

I had a bit of drama (still ongoing) with a parent EXTREMELY upset because of my grading policy for the last 6 weeks. Ultimately her child got an 87% for the semester, but that's not acceptable to her, and I've ruined her child's life, and she'll be speaking to my administrator to make sure I don't have this opportunity EVER again to do this to another student. Deep breaths. I've talked with various other teachers and friends and have calmed down a bit, but obviously I'm still bitter.

In brighter news: I've started "playing" the guitar (and by playing, I mean random strumming and posing and trying to look cool while screechy sounds eminate from the instrument as my tongue sticks out of my mouth to aid in better concentration) and am self-teaching myself (that sounds redundant) via books and cds and dvds. It is so fun.

I'm also planning on making a simple big-square quilt for our guest room this week, so that when my friend visits, I won't have to subject her to the 80's style black-neon-pink-&-green-&-purple syntheticy cover.

Calculus project news. I liked how my volumes of revolution foam projects turned out. BUT. I have an idea I want to play around with for a teaching tool for next year. I'm thinking of getting card stock or laminated color paper and cutting the same shape out many times. Then I'll either cut a hole in each one or a slit in order to string all these shapes onto a circular thin wire or stiff cardstock that is curved into a circle. Then I can "fan out" the shapes or clump them together, and the students can get a better visualization of a "volume of revolution". I'll have to experiment this summer.