Day 99 – Pressure and Math Cubes

Science 8 – Here is a photo from my other science 8 class. I used math cubes to model pressure. Each block represents one unit of force and the height of the blocks is units of pressure. Each block that touches the desk is a unit of area. We make a chart on the whiteboard with pressure, force and area and the students are asked to find patterns. Eventually we see that pressure x area equals force. Voila! we have P = F/A.  12 cubes works the best because factors.


I suppose you could call this “discovery learning” and I have no idea why you wouldn’t want children to experience it. They are challenged and engaged in the activity and feel pride at the end of it. Some educators say that we should simply tell them P=F/A, in order to reduce their cognitive load.  I guess this comes down to what you value in education.  For me, I simply cannot imagine what is so important about P=F/A such that a student really needs to know anything more than the idea that surface area spreads force out.  And frankly speaking, most of high school science is like this.  For me, the process is the important part.  Challenge their reasoning, their ability to make inferences, to recognize patterns and turn them into a model that can make a prediction.  That’s what I’m talking about.

Day 92 – Imploding Pop Cans

Science 8 – We did a couple of labs with pressure today. Of course the imploding pop cans was the highlight.

It’s kind of funny – I didn’t give the class specific instructions on using the Bunsen burners today even though it’s been a couple of months since they last used them. Looking back, I probably should have. Not that I’m worried about there being a bad accident but more just to reinforce proper use. Anyways, the students all did a really job with the burners and making a good small hot blue flame. It was impressive.

Day 90 – Pressure

Science 8 – Students today were introduced today to the idea of pressure. I usually start off with them using math cubes to model pressure and force. The photo above is a summary from our class, not notes given out at the beginning. Sometimes it is valuable for students to make their own summaries but for today’s topic I felt that everyone should have the same content and message.

Pseudo Day 121 – Pressure


Science 8 – May 13

I used math cubes to model the concept of pressure. The idea is that the height of the cube stack represents pressure.  The number of cubes is the force, and the number of cubes touching the desk surface is the area.  Stacks have to be even in height.  Using groups of 12 cubes gives several different configurations. I highly recommend this activity for introducing pressure!