I am enjoying teaching math this year. Number talks seems to happen naturally a lot in kindergarten, and the activity that I did today included students thinking about estimation and mental math. This was my introduction of the estimation jars to the children. I first showed students the middle jar (with 5 balls). I asked them to estimate how many balls were in the jar. I lot of kids counted, others took a quick guess. We took the balls out and counted them together. We discussed how our estimates do not have to be exact, but also how one thousand would not be a good estimate for the number of balls in the jar.
I then showed the jar with 2 balls. Students estimated how many balls they saw and were encouraged to use words, such as more than or less than the other jar. Finally, I showed the final jar with the most number of balls. This time I only quickly showed the jar and then covered it up. I wanted students to do a quick estimate without having the option to count. I got lots of great estimates. I encouraged explanations for student answers. Some students were able to vocalize that they estimated that there were about 10 balls because they knew that it was more than the middle jar, which had 5, and they thought the jar looked like it had about double. Lastly, I had a volunteer put the jars in order from least to greatest.
The jars with the colourful balls work well to keep students attention and encouraged conversation. I can’t wait to keep using the jars for number talks. For the fall, I plan to fill the jars with small apples, or acorns and keep switching the contents up for each number talk.