Day 147 – The Expanding Universe


Science 9 – As part of their learning about the Big Bang and the expanding universe, students do an activity where they model this expansion with balloons.  They noticed that all of the galaxies move away from each other and that the expansion goes in all directions.  To help with these topics, I’m using parts from the Perimeter Institutes resource package.

Day 126 – Models


Physics 11 – Today was mostly seatwork/practice. However, I did spend a bit of time going over models.  Even though it’s something that they’re supposed to be working on all year, I get the feeling that I call these things models and the students just think of them as a list of things “to know.”

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 80 – Formative Assessment


Science 8 – We have spent three days looking at these two models. Day one was discussing prior knowledge (exploring), day two was a lab activity (explanation) and day three was extension (practice questions).

The two stars and a wish is a tool for kids to try and summarize some things they’ve learned and to show themselves and me where their gaps are. It can be useful, but only if the teacher is committed to spending time working with the input from the students.

Day 72 – Particle Model


Science 8 – I love this lab. Students predict what they’ll get when they mix 50 mL of water with another 50 mL of water, and then they find out that it’s almost 100 mL. They do the same with 50 mL of water with 50 ml of ethanol. To their surprise, it only adds up to around 97 mL. Finally they mix 50 mL of sand into 50 mL of marbles. They now have a model for how matter is made up of particles and how there are spaces between the particles.  Students also learn about miniscus, graduated cylinders and brainstorming errors (why did 50 mL of water + 50 mL of water = 99 mL?).

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!