Number Talks – Bumps in the Road

Today, I presented, with my colleague, Denise Anderson, a session on Number Talks at the Minnesota Department of Education.  The topic was ‘Where do we go from here:  Managing bumps in the road.’

Here are the slides if you are interested:

I’ll be presenting this session as a webinar on Tuesday, May 24th.  Details here:

My favorite slide:  0513161500



Something to Talk About

It’s April.  Have you heard of April?  It’s that month of the school year where all students can see is the finish line, and all teachers can do is expend a never-ending amount of energy trying to motivate students in these final weeks before summer.  I mean, come on kids, it’s not even May yet!  There aren’t even leaves or goslings or temperatures consistently above 40 for goodness sake! There is so much learning to be done before we send you off into the summer sun!

Anyway, I haven’t done a Number Talk in a couple of weeks because of spring break and MCA testing.  I decided to begin anew today, and this was a treat.  We reviewed the norms, fired up our brains and got to work on 250 x 28.  When I asked for students to volunteer their answer, I got 4 incorrect answers along with the correct answer.  Second period, much to my delight, they contributed four different incorrect answers as well as the correct one.  Students who are hesitant to share were willing to explain their strategies to the class.  With their permission, I’ve included their names with their strategies:

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These 9th graders are doing a spectacular job of working together in cooperative groups as well.  When I give them something to discuss with respect to probability and statistics, they really challenge one another respectfully and support one another appropriately.  This doesn’t necessarily happen naturally but is instead developed through consistent expectations of shared group responsibilities.  Overall, it’s a tough time of year to be a high school student with summer looming.  I’m very proud of the progress my students have made thus far this trimester in making sense of all the data around them.


Stringing Students Along

If I’ve done one thing consistently this year, it has been Number Talks in my Probability and Statistics classes.  I have seen students who, at the beginning of the trimester, told me flat out, “I can’t do math in my head.” Now that Trimester 1 is coming to an end, those same kids are volunteering multiple strategies in these mental math challenges.

During the trimester, we started with the dot image below and have moved through the four operations, onto decimals, and even dabbled in fractions and percents.


How many dots are there?  How did you count them?


What’s important to me with these number talks is the visible improvement I saw in my students’ confidence and flexibility with numbers.

I’ve shared before about my experience with number talks and I plan to continue these throughout the rest of the school year.  But at the NCTM Regional conference in Minneapolis a couple of weeks ago, I had the pleasure of attending Pam Harris’s session on Problem Strings.  I found that problem strings are very useful when wanting to elicit certain strategies or move toward generalization of a strategy.

Here are my notes from a problem string I did recently with the same group of students I have been doing number talks with.


I noticed:

  • Many students did not use “17 sticks in a pack” to figure out sticks in 10 packs
  • Many more strategies than expected were shared to find the number of sticks in 6 packs of gum.
  • Most students were able to generalize about number of sticks in n packs.
  • Participation increased with the multiple opportunities to volunteer their strategies.
  • Students could see relationships between the numbers and find the solution in multiple ways because of that relationship.
  • There are many implications of these problem strings in secondary mathematics. In this example, the slope formula can be easily elicited through further exploration of the table we made.

I’ve read all of Pam’s books, but getting to see her present problem strings in person really illuminated how these can be useful in my classroom. Thanks, Pam, for opening my mind to this and letting me fangirl you.  I’m looking forward to doing more of these, including recording them.  Stay tuned.