When does a rock stop being a rock?

When does a pebble stop being a pebble and become a stone?
When does a stone stop being a stone and become a rock?
When does a rock stop being a rock and become a boulder?

I ask my wife these three questions too frequently. She's had enough of my philosophizing. So maybe you can help me out here? Are the answers too subjective? Is there an objective, definitive, agreed upon set of answers to these questions? Are the answers determined by weight? size? volume? mass? density? ootsies? (a la Christopher Danielson)

I'm thinking bigger picture here: How do we bring this type of thinking or wondering to our students more often? When dealing with measurement, how do we get our kids to know the correct (or most logical) way to measure quantifiable items without telling them? Would asking these types of questions help encourage our students to be better problem solvers or be better at applying the right terminology?

So many questions... here's more:
Living in the USA, our customary units system of measurements seems counterproductive with inches, feet, yards, fathoms, miles, ounces, cups, pints, quarts, gallons, barrels, etc. Terminology can be difficult enough for students and to throw all these different measurements at kids (nay, humans) can only seem daunting. When should we use feet to measure something instead of inches or yards? I envy the metric system and, well, let's leave it at that. These measurement questions become even more relevant as I dive into estimation with my students and as I update estimation180.com each week.

I haven't posted in a while and feel like I need to ease back into my blogosophy (blogging philosophy?). I'm not sure I just eased back into it. What do you think here?

Rocky,
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CMC - South: What could be?

November 2 and CMC South are only a few days away! I'm excited for a few reasons:

1. World of Nathan Kraft is flying in (if Hurricane Sandy isn't too absurd this week) from PA to attend. I'll pick him up and we'll carpool to Palm Springs for the conference.
2. Fantastic Fawn is literally missing her favorite football 'game of the year' to attend and cause some trouble with Nathan and me.
3. Mullet King Matt Vaudrey is both attending and presenting.
4. Recent doctorate and newly appointed Mathalicious brain Matt Lane is making the trip.
5. The infamous Dan Meyer is presenting (need I say more?).
6. ... and there will be a Tweetup on Friday with all these fab people, hopefully with John Berray too.

There are some appealing conference speakers this year. I wish there were more on Standards Based Grading. I think the two presentations I'm most looking forward to (besides Dan's) are Standards Based Grading to Evaluate Mathematical Practices by Lisa Miller and Take Your Places by Brad Fulton. I've seen Brad present before. He has got some great ideas and is hilarious with a capitol H. Sorry Mullet Vaudrey, I truly wish I could be at two places at once. Video record yours and post it, will ya?

I'll admit, there are parts of me that would get a kick out of the following:

1. Nathan checks his tuba at the airport, pays the outrageous fee, and carries it around CMC testing out the echos. Heck, we are in the desert, but there is a small mountainside nearby and we could test the echo off of that sucker. 
Tuba Echo from Nathan Kraft on Vimeo.

2. Matt Vaudrey needs to sport a mullet the entire CMC (if he hasn't grown one out by now) and have his camera ready to take pictures of some locals with mullets. I'll bet Matt a beer that by the end of Friday, we spot at least 3 mullet-y locals worthy of your ratio lesson for this year.
3. Fawn, better bring me that box full of avocados she owes me from File Cabinet. I'm tempted to pack my OG Nintendo and Tetris so we can have a little Tetris showdown. That way, she can't cheat on her Xbox (Okay, she might still kick my butt). At least I'll stand a better chance, right? If she doesn't bring me the avocados, maybe she'll bring me all her Brad Fulton books so I can steal, I mean copy them.
4. As for Dan Meyer, I'm looking forward to meeting him and actually looking up at someone for a change. I'm speaking of height here people. I look up to everyone mentioned in this post! However, wouldn't it be fun if our Twitter group heckled him during his entire presentation?

Stay tuned for a full report from CMC and some fun contributions to Estimation180.com

CMC to be,
930

Transversals, Tape, and Stickies

Today in Geometry, we're discussing two lines, a transversal and the angle relationships formed. We did a few minutes of word wall pics and direct instruction of Corresponding angles, Alternate Interior angles, Alternate Exterior angles, and Same-side (or Consecutive) Interior angles. Then students were presented with the following setup on my walls. I used three strips of masking tape to create the lines intersected by a transversal and numbered stickies. I was able to set up 3 stations since I have a small group of 8th grade Geometry students this year.

Students worked in groups and were instructed to start with the two parallel lines and the transversal. It's a lower entry point as opposed to the three lines intersecting to form the triangle (which my textbook chooses to introduce this concept. Silly publishers). Groups are given the following handout and need to place the stickies in the correct places, based on the given clues. Work together, GO!
Handout and solutions here.

If you have limited space, create 1-2 stations and have groups rotate as other students are completing a task at their desk. Put a timer on the board and tell the students to get as far as possible within the allotted time. When the timer finishes, I'd take a picture of their work, reset the stickies, and let another group tackle it, resetting the timer.
Here are possible solutions. Let me know if you find any errors.

It went well. There was a lot of tension in the groups. Some kept moving stickies around because they disagreed. They disagreed because of the overall connection, not because of getting the relationship wrong. It was so fun to hear them get so excited about this activity. We ran out of time and the quote of the day came from a girl, "That's upsetting me." She wanted to finish. She wanted to know the answers. She wanted to figure out the puzzle. Many other students had similar feelings. I love it!

What I learned: Don't make the groups too large. Go with about 2-3 students (4 max) per group. Use really good stickies. The orange ones you see in the pictures were old and had lost their stickiness. If groups are struggling too much, encourage them to find a set of angles that has the least amount of possibilities.

Transversals,
1239