Warm-up Level-up: Estimation 180

I’ve been working on improving my warm-ups and want to blog about them so that I keep doing beneficial things!

Previous Warm-up Level-ups:

In the Beginning

When I first found out about Andrew Stadel’s Estimation 180 activity, I thought it was a great idea and wanted to implement it in my weekly warm-ups. I had two estimations each Friday (so not 180 of them) and this has always been the most popular warm-up ever since I started a weekly routine of these warm-ups. I tried to make the second one related to the first so that students had some ability to make a more educated estimation.

I used to call on students or asked them to shout out their guesses, and proceeded to write all the guesses down on the whiteboard. As many teachers have pointed out, getting the students to say or write down their guess gets them to have “skin in the game” so they’re more invested in the answer. But this was time consuming and every student didn’t always feel comfortable shouting out an estimation. The bigger problem was that people tended to follow the first estimation, reducing the amount of thinking they were doing.


Now I have students go to a link (bit.ly/WHSestimate1 and bit.ly/WHS estimate2) on their Chromebooks and this takes them to a Google Form.


Then I look at the spreadsheet and sort by their estimation so we can quickly see the smallest, largest, and get an idea for the range of the guesses.


I then hide their name by scrolling to the right (I do this before sorting so they don’t see each other’s names). The anonymity helps shy students have the courage to submit an answer knowing they’re not going to be ridiculed for whatever answer, even if they have no clue.


I also try to emphasize and read some of the better “reasoning”, though I give the students 1 minute (via a timer) to make the estimation and explain, so that’s not always the highlight.

After looking at the estimations, I reveal the answer (often by waiting excruciatingly long!). I go back and show the winner(s). The winner gets to have the “rolling chair” for the day and the upcoming week until the next Friday. If there is more than one, I paste their names here and randomly choose one.

In the Future

The thing I would like to do is better emphasize the “explain your reasoning” part, which makes the students think critically. One way I’ve done that is highlighting a few of the reasonings (before revealing the answer) and then after revealing the winner of the chair, I’ll reward those who had good reasoning with candy. Or sometimes I’ve said “the winner must have decent reasoning” so all the “idk” entries couldn’t win. But then there’s the gray area of “What makes good reasoning?”, which is, I suppose, a good discussion that I need to be willing to embrace, even though it makes me a little nervous to have if only because there’s no clear “right answer” to that question as there is in most of math.

I do like how this warm-up moves quickly (if I set a timer, the students know they should open up their Chromebooks before the bell rings to not miss the 1 minute deadline!) and how students are highly motivated to participate. What’s fascinating to me is that in classes where there are one or two students who “don’t care about any of this math” they are very eager and excited to try the estimation.

The other way I want to improve this warm-up is to make it more personal for the students. Andrew Stadel’s stuff is great, but one of the top questions I get is “did you make this video?” and I’m forced to answer “no, one of my math teacher friends[1] made it.” Some of the best warm-ups are ones that connect to the students lives[2] and I’m slowing replacing Andrew’s warm-ups with my own photos and videos. The more I can make it about them and/or me, the better our relationship and the better they’ll learn in the class. These types of warm-ups just beg to be made more personable and this is such a good opportunity for just that!


[1] I’ve met Andrew in person once, so that counts, right?

[2] One of my favorites is taking a photo of a combine harvester at the county fair during the week of the fair as many of our students are highly involved in the county fair.  There was a sign for the price of the harvester and many students exclaim “hey, I saw that sign!” but then struggle to remember the value of the harvester!

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