Number talk today:
Many kids found the precise answer within a minute, and there weren’t major misconceptions from the students who shared. That said, the big idea I’m looking for in most multiplication number talks — effective use of the distributive property — didn’t come from as many kids as I would’ve hoped. There were basically three camps:
- Students who found creative ways to multiply — for instance 51 x 9, then double the answer, or rounding 18 or 51, or 51 x 6, then triple the answer. All great strategies, but not quite what I was hoping would come out.
- Students who made use of the distributive property (usually by finding some way to calculate 18 x 50, then adding one more 18), but didn’t make that clear from their explanation.
- Students who used the distributive property, but were clear about breaking apart (for instance) the 51 into 50 and 1, and multiplying the two parts separately.
I would estimate students were about 30% using #1, 60% using #2, and 10% using #3.
This isn’t a big misconception, but students will be more powerful mathematicians if they can name and work flexibly with the distributive property.
Today made me think more about the way I scribe answers. Starting in my second class, I made a significant effort to probe students to be more explicit about their use of distribution, and to scribe it in a way to help other students make sense of it. I’ve had a desire to give more student ownership to number talks — for instance student scribes, or more partner-based interactions. But today reminded me of the value I have as the teacher — of taking a mathematical concept that one student is using effectively, and making it clear and accessible to the rest of the class. That’s not the student’s job; it’s mine. The best way to make that happen, however, is something I’m still working on.