Seven days in, and I am sold on Number Talks.

I had been hearing about Number Talks for a couple of years, but it was finally Megan Schmidt's persistent updates on Twitter that made me try them in earnest this year.

If you haven't heard of Number Talks, read this book. But if you want a short summary, here is how a number talk works:

- Put an arithmetic problem, such as 111 - 29, on the board
- Students place a fist on their chests and raise their thumb when they have an answer (and other fingers when they have multiple strategies)
- Record all student answers without indicating the correct answer
- Ask for volunteers to defend an answer and explain how they solved the problem. The teacher tries to take notes on the board that replicate the student's thought process
- Ask for more and more, never giving away the correct answer. It will become clear to the students anyway
- Pick something cool or interesting from a student strategy and highlight it or ask a question about it.

So far, my goal has not been mathematical, but instead to model and promote the sort of mathematical conversations I want to hear in my class. But because my students are awesome, we got some great mathematical conversations anyway!

For example, in one class a student solved 111 - 29 by "sliding" the problem up by one, up to 112 - 30. I asked for another student to explain the strategy and then modeled it using a number line.

It became a favorite strategy all week for kids, until Friday when a student used the method to slide 5.1 - 0.35 down to 5 - 0.34. This promoted a GREAT conversation about why we need to be precise with our language in math class. Kids had been saying "five point one" or "point thirty five" but then switched to "five and one tenth" after this conversation. I think this will be a more memorable lesson because it came up in the context of a mental math problem that students had thought deeply about.

I will probably start recording some of these talks and transcribing the best bits for future blog posts. Seriously, I wish I had a court stenographer in my room so I could just show you guys how great the conversations have been already.

Also I have a big idea about using Number Talks to teach about the properties and how to manipulate algebraic expressions, but that's for another day. For now:

### My tips for starting Number Talks

1) Read Making Number Talks Matter. Seriously, it is such a good book. It's full of great classroom tips to promote and deepen student thinking using the Number Talks structure.

2) Start with dot pictures. This is a tip straight from the book, and it's great. I did three days of dot pictures, which helped set a norm that I expect lots of answers and lots of participation. On the first day I used this picture:

And just look how many ways my students saw this answer:

3) Have the kids stand up. I think it sets a tone that this is using your brain in a different and more active way than most warm-ups. Besides, kids have fewer distractions when they stand.

4) One idea I haven't started yet is to have a Great Mistakes board to provide an incentive for students to share their ideas, even if they may be wrong. The idea is to give each class points whenever a student makes a mistake that leads to a valuable learning moment, such as the place value error in the decimal problem above. Extra points for a student who bravely shares something they did wrong and explains why it was wrong or how to correct it. When the class gets to 10 (or 20 or whatever) points, the whole class gets a prize. Our school is trying a positive behavioral support system that I might try to tie into my Great Mistakes board.

Good luck! Let me know how it goes!