# Day 20

Physical Science: We finished reviewing standards of measurement and unit conversions. When I went around to spot check student work, I was impressed by how much growth their was from the first practice to this final one. More students were now using the proper ratio setups. There was some math stuff to clean up, but overall I was pretty happy.

We had a small study group for the quiz during our Common Study Period, and we worked on some conversions that weren’t metric, or even measurement based. Such as if 4 pickle slices = 1 cheeseburger, then how many slices would you need for 12 cheese burgers. I explained to these kids and all my students, that ratio reasoning and unit conversions is a process, a skill. It really doesn’t matter what the units are, so long as you understand what ratios can be used for and how to use them.

Chemistry: Last week during a white board discussion the topic of gases and density came up.

Me: “Do gases have a density?”

“Yes.”

“Really? Do they have mass?”

“Sure. Gases is matter, and matter is anything that has mass.”

“Do gases have volume?”

“Well, they are all around us so, sure?”

“Sounds like we might have to investigate this.”

So I gave them a Lab Practical: a lab that is really a test of their understanding of course content, and lab techniques. They are trying to measure the density of carbon dioxide gas. Which they spent the hour trying to figure out yesterday. Of course I gave out two big hints in the handout: we already saw how to measure the mass of gas produced in an earlier lab (Mass and Change Lab) and also how to measure the volume of odd stuff (water displacement).

Today they actually have to do it. Should be interesting to see the results.

Physics of Light: They took their quiz on Pinhole Cameras, Reproductions, and Light Intensity.