Almost seven years ago I tweeted this:
Fast forward several years, one on-going pandemic including sanitized groceries, and we have revived the “Estimation Station” as a school-wide mathematics activity. Here’s how we are doing it!
Estimation is an often overlooked mathematical skill that when explored authentically can lead to developing conceptual understanding, number sense, and the kind of flexibility and reasoning that fosters mathematical proficiency.
The advantages of authentic in-school estimation experiences include students’ improvement in the skill of estimation, increased confidence, internalization of everyday mathematical expertise, and an elevated perception of the value of mathematics. Each estimation occasion that arises is an opportunity for educators to connect mathematics with the everyday lives of learners (Taylor-Cox, 2001).
Once a month each math class takes a trip to our Estimation Station, which is highlighted by the same beautiful artwork from our original estimation station created by my former assistant teacher, Diana Avellino. There they have an opportunity to make observations, collaborate with peers, and utilize the referents provided to make their best estimate of how many, in this case, Halloween fun size candy bars were in the container. Referents for estimation are a disclosed amount of the item being estimated that students can use as a point of reference.
Once students have had a concrete kinesthetic experience at the Estimation Station, they go back to their classrooms to make estimates using the range-based techniques popularized by Andrew Stadel’s Estimation 180 instructional routine. Students fill out a google form where they give their answers for what they think is “too high,” “too low,” and finally their estimate.
Later in the month, we show the students a video giving them more information regarding the amount of items in the container and then they have an opportunity to revise their estimates given this new information.
Finally, at the end of the month, we show a video reveal and announce the winner. Jennifer Taylor-Cox warns against extrinsic rewarding for the right answer. “The aim is to estimate within an appropriate range. Still, many students desire to estimate the precise amount. To combat this “right-answer syndrome” often associated with activities of estimation, I use such terminology as actual number instead of correct or right answer. I encourage my students to evaluate their own estimations independently, using adequate ranges that encompass the actual number. I teach my students to try to “sandwich” the estimated actual number. Visualizing upper and lower numeric cutoff points as slices of bread that sandwich the actual number serves as a vehicle for young children to comprehend the abstract notion of ranges.” We do have a winner who is extrinsically rewarded, but only after making an estimate within a reasonable range and revising their estimate given more information. So, ¯\_(ツ)_/¯
If you wan to try an Estimation Station in your class, here are links to copy our February Estimation Station google forms with videos:
If you do try it, let me know how it goes! Or if you are doing a different school-wide mathematics activity, please share. We are still looking for an activity for next school year!