Wednesday, February 1, 2017

Student Journal: Introduction to Equations (Days 92-93)

Here is today's Pappas question of the day:

Find the perimeter of this quadrilateral in meters: sidelengths are 100 mm, 20 cm, 3 dm, 0.4 m.

We can solve this using dimensional analysis:

100 mm (m/1000 mm) + 20 cm (m/100 cm) + 3 dm (m/10 dm) + 0.4 m
= 0.1 m + 0.2 m + 0.3 m + 0.4 m
= 1 m

So the answer is one meter -- and of course, today's date is the first of February.

Today the eighth graders begin working on solving equations. It's the first standard that overlaps somewhat with Algebra I -- yes, the geometry part of the year is over. This is the specific standard that they are working on:

Give examples of linear equations in one variable with one solution, infinitely many solutions, or no solutions. Show which of these possibilities is the case by successively transforming the given equation into simpler forms, until an equivalent equation of the form x = aa = a, or a = b results (where a and b are different numbers).

What's strange about this standard is that I think of it as covering the simpler one-step and two-step equations, while EE7b covers the multi-step equations.

But note that any equation whose simplest form is a = a (with infinitely many solutions) or a = b (no solution) must necessarily begin with variables on both sides -- and adding or subtracting to eliminate the variable from one side makes it disappear from the other as well. So this section already gives us multi-step equations. And in addition, some questions require the distributive property to simplify. So in a way, the students are already learning EE7b.

With so many multi-step equations, of course the students struggle with these. A few of them are able to figure out how to solve these.

During the new SBAC prep time, some of the practice test questions were on slope. Of course, I had to give the Sarah Carter "Slope Dude" example with Puff Puff Positive Slope, Nice and Negative Slope and all of that.

Meanwhile, just as I feared, science was another disaster, But this time, it happens because students say they need extra help on the Student Journal math assignment and so math continues into the time for science. On one hand, the students probably do need the extra help, but on the other, the extra page I cover gives the multiple choice "one solution," "no solution," and "infinitely many solutions" for each question. So many students just mark one of these boxes without doing any work -- that is, the "we need time to finish math" is just a ploy to avoid doing math or science, especially as this is the third hour that they are in my room on the new schedule.

Well, at least it gives me more time to collect materials for the science project. I'm still not sure what magnetic "powder" I'm supposed to use in the project (as the Illinois State science teacher edition doesn't actually specify). I know that iron, cobalt, and nickel are the three magnetic elements, and I see some "steel wool" in the store that is slightly magnetic. I'm keeping the project ready in my cabinet -- if another argument about how I don't teach science breaks out, I'll take out the project no matter what day of the week it is.

Speaking of Sarah Carter, I'm still at awe over how the famous math blogger -- another math teacher who had science unexpectedly thrust upon her -- can be so successful in her new subject. For example, in her January 23rd post, she writes about a successful lesson based on Glow Sticks:

I wonder whether I should attempt a Glow Sticks project or not, especially since I found some in the store while looking for the steel wool. Then again, I should be giving only Illinois State projects.

This is a two-day post -- with the second day scheduled for Illinois State learning centers, which may be another adventure. My next post will be Friday.

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