Parentheses
Exponents
Multiplication
Division
Addition
Subtraction
I remember this acronym well from school. But it always confused me: Do I follow PEMDAS within the parentheses? Am I supposed to work left to right?
I headed over to Khan Academy and watched an introductory video. (Oh, yeah! PEMDAS is also known as the order of operations!)
The first thing I learned that I didn't remember was that Multiplication and Division are at the same level--it's NOT multiplication first, then division; instead, you work left to right. Same thing with Addition and Subtraction. So I'm rewriting this acronym:
Parentheses
Exponents
Multiplication/Division
Addition/Subtraction
Although I got the answer right on my first test question even though I treated MDAS as all separate items. Hmmm. Someone in the comments had that experience, too, it turns out. That commenter said sometimes it will work and sometimes it won't, depending on the problem. And the lesson added that if you have ALL addition or ALL multiplication in a problem, you don't have to worry about what order you do them in.
Time to practice:
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| Problem 1 |
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| Problem 2 |
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| Problem 3 |
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| Problem 4 |
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| Problem 5 |
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| Problem 6 |
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| Problem 7 |
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| Problem 8 |
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| NAILED IT! |
That wasn't so bad. . . .
I love this site so far, by the way. I went to the Common Core website mentioned in the instructions for the PLP, and a search for PEMDAS brought up no results. But at the top of each question on KhanAcademy, it had the Common Core standard at the top. And it turns out that order of operations is taught in sixth grade:
Evaluate expressions at specific values of their variables. Include
expressions that arise from formulas used in real-world problems.
Perform arithmetic operations, including those involving whole-number
exponents, in the conventional order when there are no parentheses to
specify a particular order (Order of Operations).
Khan Academy's layout of the Common Core standards is so much easier to read than the other site's!
Next week: Geometry.
I love this website! It's so straightforward and describes each lesson well! This was a great topic and was a good refresher to make sure you have the correct order of operations.
ReplyDeleteI will have to check this website out! I usually spend a lot of my time when it comes to my PLP googling which worksheets or activities are available, so thanks! I also like that you were able to find the common core standards to apply to all of the problems you did.
ReplyDeleteI have been loving the Khan Academy! The videos are awesome - really helps me understand what is going on. Thank you for this refresher, and I like how you rewrote the acronym. I completely forgot that multiplication/division and addition/subtraction are on the same level, so I would have definitely done problems incorrectly if just following the PEMDAS acronym. Now I have to remember if they are on the same level, to just work left to right! I feel like this definitely could be difficult for students to remember, so I wish there was a different way we could teach the acronym for order of operations.
ReplyDeleteThanks for the peer feedback everyone.
ReplyDelete