Day 173: Staggered Starts

In high school, I ran the 1600 and 3200 meter races. In one particular 3200m there were over 50 runners on the track. I was placed in an alley made up of lanes 9 and 10 and was out in the middle of nowhere, already halfway around the curve. We cut in at half a lap, it seemed like I was way ahead but ended up landing in the middle of the pack.

Here is what geometry looked at today:

*I mashed together a few problems/resources to put together this problem: 1        2        3

TrackThe first question I asked students was “If all the runners started at the same place, how much more distance would the runner in the 8th lane cover compared to the 1st lane runner?”

We put a few guesses on the board then they asked for some info, I ended up giving ’em this:

Track2The surprising piece is the straights of the track aren’t 100 meters… I think there is the possibility of an awesome problem within that piece of information that would really get students thinking (maybe designing a track or something). Not quire sure how to approach it though.

They went on their way, after a few minutes I introduced some structure.


They finished the table then I asked ’em to make it fair and on a picture of a track, find where the staggered starts should be so every runner ran exactly 400 meters. I lost a few of the students at this point, they were pretty stubborn in moving forward. so the problem just hung loose at this point for the rest of the period. When I try it again next year, I might stretch the thing into a period and a half or so.


Day 150: Ticket Roll (Student Work)

Continuation from yesterday’s post.

There were some interesting ways students went about finding the total tickets, have a look.

IMG_0613 IMG_0614 IMG_0615 IMG_0616 IMG_0617

I have been working on transitions within 3-Act problems.They always start really well then student engagement and quality of work slowly decline. Folding a sheet of plain old paper into 6 regions and having a purpose for each region has helped quite a bit.

For those interested

  1. Estimate: Guess, low, high
  2. Info they need
  3. Game plan of how they will use that info
  4. Provided information
  5.  and    6.    Work

One strategy that worked well today was I had students share out their confident calculations. I threw ’em on the board and then whoever had the closest talked about their solution process.

The tail end of lessons seems to be a weak spot in my daily instruction, I’m interested to hear in what sort of closing routines you all have.

Day 149: Ticket Roll

Geometry took a concept test today and started on The Ticket Roll from 101qs.


3-Acts are a lot of fun, I have been working on having students develop all aspects of the problem: from the initial question I shift their thinking to what information they need. Then before giving it to ’em I ask how they would use their desired info. Here is the list my class came up with.


A couple students reached a final number but a majority took the problem home, I am looking forward to hearing their solution methods tomorrow.