What's Wrong With PEMDAS?

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Objective

SWBAT debunk a classic order of operations myth.

Big Idea

It's easier to come to terms with a misconception when you know you're not in it alone.

The Number Trick Project is Due!

5 minutes

6 divided by 3 times 2 is...

20 minutes

Quiz Return

5 minutes

In addition to the first project of the year being due today, students get their first quiz back.  This is another opportunity to talk about how this class works, especially in terms of Mastery Based Grading.  It's also an opportunity to cultivate a growth mindset in each of my students.  I post a frequency table of scores for the class (example: Patterns Quiz 1 Results Pd4).  I point out that no on got a 0 on this quiz, and how I'm impressed that no one left anything blank.  I know that some students are disappointed with their scores, but I remind everyone that it's September, and now we all know that we've got some learning to do in this class, and that it's going to take some hard work.  I also point out that no one is perfect yet: everyone has room for improvement.

I tell students that they'll have another go at this same quiz - just with different numbers - in two weeks.

If there's time, I may take questions about the specific problems.  We usually have time to go over an answer or two, but more importantly, I tell students that they're going to see a lot of patterns this year, so there will be many opportunities to continue this work. 

Homework and How to Do It

5 minutes

As referenced on the Weekly Homework Sheet that students received on Monday, tonight's homework is in the textbook.  I remind students that they should write a "perfect heading" on their paper, and what that looks like, and I also point out that the answers to the odd problems are in the back of the book.  

This homework consists of 18 arithmetic expressions to be evaluated using (correctly!) the order of operations.  I'll use a few examples from the assignment in tomorrow's opener.