WCYDWT Live: Dirt

I found our last live session fun and extremely profitable. I’m grateful to everyone who participated live in the DimDim room and later in the comments.

I’d like to pull in twenty more volunteers to play around with a math problem tomorrow afternoon and test out some of my recent modifications to the instructional design. If you can commit 45 minutes, please drop a comment in the box using an email address where I can reach you tomorrow. We pulled a lot of people off the waiting list last time, so consider adding a comment even if twenty people have already signed up.

I'm Dan and this is my blog. I'm a former high school math teacher and current head of teaching at Desmos. He / him. More here.


  1. Jennifer Foster

    August 20, 2010 - 11:45 am -

    I am interested in playing around with a math problem tomorrow. I am currently getting ready to teach senior math and reading your website and seeing you put great ideas into action is reassuring.

  2. Why must people get married when I could be discussing math curriculum?
    Looking forward to reading the results thereafter :)

  3. Something came up, and I won’t be able to do it today (comment 16 above) — looks like there will be plenty of people to take the spot. :)

  4. Dan,

    Has there been a DimDim invite sent to those participating? It’s 3:11 on the east coast and I’m thinking that I missed my shot.

  5. This thing’s running at 3:00 PM on the Pacific which means 6:00 PM Eastern.

    If anybody knows how I can possibly make the time zone thing any clearer, I’m all ears.

  6. You know, Dan, I got a little confused about the time as well, because it says 3:00 Pacific STANDARD Time on your graphic, but most of us Pacific folks (if not everyone?) are on Pacific DAYLIGHT Time right now. So, I made sure to be home before 2:00, just in case, then realized I was converting backwards, so that 3:00 PST would actually be at 4:00 PDT. So I figured I’ll keep an eye on my email shortly before 3:00, and if that doesn’t work, slightly before 4:00. It sounds, from your 12:34 post (my favorite time of the day, 1-2-3-4), like it’s going to be at 3:00 pm “regular” time (i.e. PDT).

    As for increasing clarity next time, perhaps do what TV show ads often do: just list Pacific and Eastern times and let the Central and Mountain folks work inward from those “boundary” times. If you wrote “3 pm Pacific/6 pm Eastern”, I imagine that would remove most (if not all) of the confusion.

  7. And as a possibly-interesting side note, it appears that the time stamps on comments here are given in PST, so my “1:11 pm” comment was actually written at 2:11 pm on all the clocks in my house (here in Oregon, on PDT).

  8. So I feel the need to explain, I didn’t misunderstand the time – 3pm PST is 6pm here. Got it. Had it. All over it.

    I thought that I missed the DimDim invite and I wanted to ask early, hence the reference to 3:11pm EST.

    Sorry for the confusion…though I am wondering What Can I Do With This confusion about timezones.

  9. Trying to find another way to check the soil density, I found (on the internet of course) a range of 1-2 grams per cubic cm for desert soil, and also tried (at my son’s suggestion) lunar soil, which gave me a range of 1.58-1.74 g/cm3. I arbitrarily chose 1.6 g/cm3, which I converted to 99.9 lb/ft3. Not that far from the number we used (120 lb/ft3). Rounding to 100, I still get a yearly total of 173.25 tons of dirt. Astounding!

    So, if X-Ray dug about 1000 pounds *less* of dirt each day, how much dirt are these boys digging, anyway? The 5-foot shovelers dig almost 10,000 pounds, I calculate. 3% less shovel digs approximately 10% less dirt.

    Other extensions:

    How much shorter would a shovel have to be for a boy to dig half as much as the others?

    What size of a shovel would a (very, very small) person use to dig a hole with only 100 pounds of dirt? [Like a textbook comparison of cube-to-cylinder volumes.]

    Thanks again for the meeting, Dan!