Does Mint Really Make Your Mouth Cold?

You know those days you dread as a teacher… the ones where you have a pep assembly or a bus evacuation practice that messes up your schedule so that you only see some of your classes, but not all of them. Teaching middle school science makes it even worse… you either have to fill a day or have a class or two behind until who knows when. 

I had that day. I had been dreading it all week because the weird schedule can be so hard to come back from. My 7th graders were learning the difference between qualitative and quantitative data. I wanted to give them something they could do to practice this skill without killing a day.

That’s when I came up with the idea for the Mint Lab. The Mint Lab answers the question, “Does mint really make your mouth cold?” 

Goals of the Lab

As an adult, I know the answer is no. But this was just the kind of misconception that my middle school science students would have – a perfect, simple question to test!

I had three goals with this lab:

1. Collect and record quantitative data from an experiment.
2. Show them their hypothesis can be incorrect (about half guessed it made water cold, the other half guessed it didn’t.
3. Use the quantitative data to prove their hypothesis correct or incorrect.

Set It Up

Each student got a Lifesavers Wintergreen Mint as they entered the classroom. The task on the board asked them to write qualitative observations about their mint. They said things like, “It’s a circle… the lifesaver is white… minty… hard… small… there’s a hole in the middle… my mouth feels cold (!!!)… I can feel it in my nose…”

“Take a deep breath through your nose. Does your mouth feel cold?” About 75% raised their hands. I broke them up into lab groups after I gave directions (check out my grouping cards here! Life savers… ha get it?!).  

The Lab

Here is the idea of the lab: Fill two beakers with water. Record the temperature of regular water every 30 seconds for 4 minutes. Add the mint to the second beaker of water and record the temperature again every 30 seconds for four minutes. Compare the temperature of the regular water to the water with the mint.

Students realized pretty quickly that the temperature didn’t change after they added the mint. They recorded their data into the tables and got to writing their conclusions. Most students could tell me that the temperature didn’t change. However, about ¼ of them said the temperature “changed” with a 1° change. I explained that the difference between 98° and 99° outside doesn’t really mean the temperature is colder, rather it’s about the same. If the temperature had dropped significantly in those four minutes, it would indicate a change in temperature.

(Because of this misconception, I added a double line graph students for students to make after they collected their data. After using it with another class – on vision testing day – the visual of the two nearly straight lines almost directly on top of each other really helped them SEE that there wasn’t a change.)

Wrap It Up

Finally, they had to use their data to make a 2-3 sentence conclusion explaining why their hypothesis was correct or incorrect. Most of them could answer that. I had to be really clear to use examples from their data to prove it. I hadn’t taught them how to write a real conclusion yet, but this ended up being really great practice. They had a very small amount of data to analyze, and it was a great tool for me to determine who really understood what I meant when I said they needed to use examples and who still needed some support moving forward.

Teaching middle school science is like that. Students walk in with varying abilities to complete different tasks. This lab helps me figure out if they need some quick reminders or if they need some heavy duty intervention. 

Overall, my 7th graders loved this lab. I loved this lab. It was easy and cost effective – mints are like$2.00 for 100! They had a real opportunity to test a question, collect data, and determine if their hypothesis was correct in a 45 minute class period.

And while this was originally intended to be a “filler,” I will use this lab intentionally with every class next year! Plus, think I got the best teacher award when I said they could eat the mints because they were SO DANG EXCITED!

I highly recommended this lab for any middle school science teacher!

Get a copy of the Mint Lab here!!