Kitchen Science: A glass bottle, an oven, and some ice water

So, today I did a little science in my kitchen. I learned some stuff and I wanted to try it out. And I’ve got a 5-year-old and an 8-year-old who are very willing to be perplexed.

Before I get into the story, I have a question for you.

Imagine you heated a glass bottle (maybe the 12-16 ounce variety) in the oven at 450 for 10 minutes or so. Then you took it out, turned it upside down and placed it quickly about an inch or so deep in a sink of ice water.

What do you think would happen?

Leave your prediction in the comments or e-mail them to

We did this exploration in the kitchen. It led to some good perplexity and some great wonderings.

In my next post, I’ll share what happened.

A word about fractions

This story begins with a tweet that I read.

This tweet poses a nice engaging situation where addition of fractions would be a very useful tools. But, addition of fractions involves common denominators. And, then I began to remember my students attitudes toward fractions, which can be summed up by the following…


… clearly fractions are so difficult that it requires someone with the reputation of Chuck Norris to be able to deal with them effectively.

Except, they aren’t. Or maybe they are, but they certainly don’t need to be. The logic that says that 2 min + 31 sec doesn’t equal 33 of anything is perfectly understandable to most. It’s the exact same premise as requiring common denominators to complete a fraction addition problem. And THAT is confounding to many. It seems like an arbitrary rule that math teachers invented to trick students.

And the teaching of it carries with it some strong opinions, too. I remember during my undergrad, one of my professors asked this:


One of my classmates changed his major that day. He got so angry that it we would be discussing the possibility that a student could write that equation and could be thinking something mathematically accurate. Dude literally stormed out of class and I never saw him again.

It is possible, by the way:

About the same time I was reading the IES Practice Guide for teaching Fractions. Are you familiar with the IES Practice Guides for mathematics? The Institute for Educational Studies gathers high quality research studies on educational and catalogs them in the What Works Clearinghouse.

The Practice Guides are documents that synthesize the multiple research studies that exists on a certain subject and operationalize the findings. Recently, I explored the IES Practice Guide for Fraction Instruction K-8.

I’d encourage you to check it out. To summarize, making fractions and conversations about portioning and sharing things a common part of math conversation from the beginning can help take the natural understanding that kids have and build fractions into that context. That will give us a chance to use math talk as a tool for students to need more exact language. My preschool son right now uses “half” extremely loosely at the moment. (I’ve drank “half” my water could really mean anything quantitatively.) In order for him to effectively communicate, he’s going to need to develop a more precise definition of “half”. That will require him adding additional fraction vocab to his toolbox.

As teachers, this gives us a chance to build in some more effective language, clearly defining the fractions as numbers. As such, encouraging a lot of conceptual sense-making about the different operational quirks that are required to effectively compute when fractions are involved. (If fractions aren’t numbers, but instead are just made-up, goofy ways of writing numbers, then the rules for computing them are goofy and made-up, too.)

The practice guide provides some tangible steps to achieve this. I’d encourage you to check it out. Lots of steps forward to take in the area of student comfort and effectiveness with fractions.

Physics, a helicopter and cameras

First watch this (and be amazed… well, if you’re anything like I am.)

So, when the students can get past the idea that there is some foul play involved, then it becomes a wonderful opportunities to discuss the idea of frequency.

Frequency is an odd discussion because it’s got a strange unit. The “per time” can be a little challenging for students to wrap their heads around.

And the opportunity that this video provides is that here, we don’t need to immediately concern ourselves with the quantitative value of the frequency (maybe 300 RPM for the helicopter rotor, for example, or 5 frames per second on the camera), but we can begin with the qualitative value of the frequency (that the frequencies, whatever they are, are the same.)

And then it opens the door for them discussing some quantitative issues. For example, the fact that the standard unit of frequency (the “per unit time”), obviously isn’t constant. So, the helicopter rotor is RPM and the camera shudder is typically in frames per second (at least, I think. Not a photographer…) So, you’ve got some nice dimensional analysis opportunities.

Where could you take this next?

One thing’s for sure, I’d hate to waste a video like this. Fully captivating, and it only costs your 30 seconds of class time.

Source: I owe TwistedSifter credit for blogging about this video first.

Perplexity and how it appears…

Here’s a video (by Derek Alexander Muller) I think you should watch.


The critique of #flipclass aside, I’m intrigued by the way the narrator describes the value of “bringing up the misconception”. It’s almost like a thorn that creates some discomfort that only learning will relieve. This gets close to Dan Meyer’s use of the word “perplexity”.

From Dr. Meyer: “Perplexity comes along once in a while. What is it? It’s when a kid doesn’t know something, wants to know that thing, and believes that knowing that thing is within her power. That right there is some of the most powerful learning moments I’ve ever seen – so powerful that it’s really hard for me as a teacher to mess those up.”

There’s power in perplexity. I’ve seen this in my classroom on multiple occasions. It’s important to remember that there’s three distinct parts to creating what Dr. Meyer is describing. First, there needs to be something worth knowing. Second, you have to create the want. And finally, we need to empower the students so they feel enabled to know that thing. What Dr. Alexander suggests is that becoming aware of your misconception seems unsettling (leading to claims that videos were confusing), but also leads to more learning. The discomfort fed a drive to resolve the discomfort.

The tricky thing is that misconceptions are a tool you can use when they are available. Science provides a particularly fertile ground for misconceptions because so much of it is drawn from experiences many of us have regularly. Alexander uses the model of a ball flying through the air. This video uses the phases of the moon and the seasons.

The potential for misconceptions is necessarily lightened when there’s no misconceptions, so the quest for perplexity in math needs to take on a different look, proper planning and timing, and different strategies for when perplexity isn’t an available option. (Preconceived notions are just as good at times. After all, we ALL think we know something about squares!)

It’s like Dr. Meyer says, those wonderful perplexing moments only come along once in a while. We foster those moments when we have them, try to create as many as we can and we do our best every other time.


A year’s worth of questions

For the past two semesters, I’ve been in lots of mid-Michigan classrooms. As I observed teachers teach, I wrote down my questions. I wrote them down in a little black book that fit in my back pocket.

The questions serve for good reflection. They have more to do with my developing understanding than they do the teachers’ performances. That isn’t to say that sometimes I didn’t see stuff that needed to be fixed up. I did. But these questions were often meant to guide my own thinking.

Here are some of the questions I asked and the observations I made.

“How do we sell screeners?”

“What’s the role of balance?”

“Do you believe in growth mindset? It should follow then that something is true that doesn’t currently make sense to you. Probably more than one. Who do you trust to give you that growth?”

“How do you download the interactive whiteboard lesson?”

“Seems like students with speech disabilities might struggle with “stretch out the word.”

“What are the expectations with iPads?”

“Could students fill out an online form instead?”

“How could we up the engagement?”

“Don’t say this: ‘I need to pull up my rubric so I can grade you’. Say instead: ‘I want to document the different pieces of your presentation.’ ”

“Presentations are tough. That was largely wasted time. How to do better?”

“They aren’t sure what to do. And they are having a hard time staying in their seats.”

“It’s loud, but to be fair, the center activities are somewhat loud… and the parent volunteer isn’t managing the volume at all.”

“Teachers who are trying to recover their classroom management will become cold… tough… no-nonsense. Does that help?”

“What if you think-pair-share…? This is too rich an activity to only have a handful of confirmed engagements.”

“What about those four kids in the back?”

“Teacher seemed to feel her control slipping, so she went heavily to individual. Calling on kids as a control piece.”

“Big question: What is the learning target of this lesson?”

” ‘I’m going to let Mikayla have some think time here.’ What if they were all solving the problem while Mikayla was thinking?”

“What is the group’s cue that they should talk?”

“Blurting out is a problem because so many want to participate. Could they?”

“It included this beautiful moment when the teacher actually said, “Gimme fiv… oh.” and was surprised when the kids were all on task.”

“Teacher never raises her voice… on the contrary, when a kid needs more attention, she seems to get quieter.”

“Big issue here is that the students aren’t responding.”