Bellwork: Number Talks in High School

A quick primer on the “bellwork” concept in case you are not yet familiar. Every period I start class with a quick 15 problem/question/activity on the board as the students walk in. They get to work on it right away, without prompting from me. I have a few different types of bellwork that I use. They are meant to take a maximum of 15 minutes (leaving 60 minutes for the activity of the day). In general the students spend 10 minutes doing the activity/problem, and then we spend 5 minutes discussing it as a class and sharing our ideas and strategies.

One of the bellwork types that I have recently incorporated into the mix is called “Number Talk“. The number talk is a way to encourage students’ number sense, flexible thinking about multiple solutions, and the ability to justify or explain their thinking. I learned about this activity via an online sumer course entitled “How to Learn Math” with Stanford prof Jo Boaler. She posted some great videos that really helped me see how to implement the activity in the classroom.

Here’s how I implement the number talk in my classroom:

As they walk in to class, the following is displayed on the board:


I give them only a couple of minutes to solve (it’s not too complicated). For Number Talks, the majority of our 15 minutes of bellwork time is spent discussing the various strategies.

I start by asking a student for their answer. After which, I ask them to explain their thinking. As they explain their thinking, I write what they’re telling me on the whiteboard for everyone to see. Students often struggle with explaining their thinking clearly, so I will stop & ask them questions whenever they skip a step or don’t explain something fully. I will also put a name to strategies that they are using without even knowing it (distribution, commutation, etc.). The board winds up looking like this at the end:


In our discussion I place the importance on HOW they arrived at the answer, not what the answer is (it’s pretty easy so most of them get it right). There are lots of video examples online of how to implement a number┬átalk in your classroom. Here’s one such video from a 5th grade classroom:

My hope is that my students will become more flexible, creative thinkers, that they will learn to clearly explain their thinking & reasoning, and that they will know that there is always more than one solution that will lead us to the answer.

[updated 2017.01.05] Kristin Gray came up with this great idea of Number Talk Karaoke where teachers listen to audio of student explanations for a number talk & teachers can practice scribing student answers. Then teachers can compare & discuss the techniques used to scribe. Genius! Check it out here.

– Laura Wheeler (Teacher @ Ridgemont High School, OCDSB; Ottawa, ON)