In my resource room, I do informal number talks every day, if you think of number talks as a way to get students thinking about numbers. However, I have not taught a formal number talk with my whole resource class of fifth graders. I chose to do a number talk beginning with a numberless word problem to get the students thinking. It evolved into a missing number perimeter problem that used fractions.
I began with reviewing the signals used in number talks. Then, I presented the students with a rectangular shape with no numbers and asked the students to determine the perimeter. The students were very quiet. It took several minutes for the students to put out the idea that it was impossible to calculate the perimeter with no numbers. Then, we discussed what numbers we would need to determine a perimeter. Next, I added a mixed number fraction for the length and width. The number talk began at this point.
From my experience last year, I had come to believe that much of the challenge in math for my students comes from a lack of math vocabulary. This number talk reinforced my observation. My students struggled to remember and use simple but important terms, such as numerator and denominator. They also have a difficult time expressing their ideas about math.
I chose to use a picture of a real garden with a fence as the basis for the problem. Some students found this distracting. Next time, I will use a more traditional picture and slowly work up to using a pictures of real objects. I think my recording of the problem was somewhat chaotic. I did not have enough room to record all of their ideas. We did get the problem solved and most of the students seemed comfortable with the process. I forgot to take a picture of our work.
In the future, I will not mix a numberless problem with number talks. It was a useful discussion, but it made the overall process too long. I had previously introduced activities to improve math vocabulary and I will continue those. I am planning to post math vocabulary in the room to support my students. I will also post sentence stems to help my students express their ideas. I will attempt a simpler number talk next week with my students using data tables.