Discussion in 'Debate & Marathon Threads Archive' started by DrivingPigeon, Apr 6, 2015.

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1. ### TeacherGroupieModerator

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Apr 7, 2015

Oh, and on a PC I bet Alt-/ (that is, Alt plus lower case question-mark) would work to type the obelus.

2. ### MikeTeachesMathDevotee

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Apr 7, 2015

PEMDAS and PEDMAS are the same thing. It's "multiplication or division, whichever comes first".

3. ### 3SonsConnoisseur

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Apr 7, 2015

I see M/D as essentially the same operation (albeit, inverse of each other). Similar with addition/subtraction.

The way I did the problem is by treating 7/2 as a fraction, multiplying it by 8 to get 56/2, and then dividing 56 by 2 to get 28 (in fact, you'd get the same answer, perhaps easier mentally, by dividing the 8 by 2 first to get 4, and then multiplying the 4 by 7). Then I add 7, and then subtract 6 (though I *could* have combined the +7 and -6 together and just added one).

Personally, I don't see the question as ambiguous. If there aren't parentheses, the 7+7 is NOT intended to be grouped over the 2 (it may be because of my background in computer programming, where formula HAVE to use the virgule and the computer will quite clearly use the OoO as defined within its math guts, to do the problem).

4. ### czaczaMultitudinous

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Apr 7, 2015

Aspects of order of operations are taught in grade three. NOT all of PEMDAS. For example, third graders solve word problems requiring them to use multiple operations and write equations to solve. They are also using beginning algebra concepts in some activities. Definitely 4th and definitely in 5th, students are pretty much using PEMDAS as shown here (albeit with the regular division sign in most cases)

A bit off topic, but did you take any math in college, or as part of teacher preparation? I transferred my license from Virginia so I'm unclear of what Praxis are required in our state, but do NJ teachers take the math Praxis as part of certification?

5. ### 3SonsConnoisseur

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Apr 7, 2015

Not sure this has anything to do with common core, but maybe it should:

A bat and ball cost \$1.10.

The bat costs one dollar more than the ball.

How much does the ball cost?

6. ### czaczaMultitudinous

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PEMDAS is not exclusively common core, nor is problem solving. Both types of math concepts existed way before CCSS.

7. ### gr3teacherPhenom

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Apr 7, 2015

It should really be:
P
E
MD
AS

Basically, multiplication and division are done in order, as are addition and subtraction. You work from left to right, doing them in the order they come up.

8. ### amakayeEnthusiast

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Apr 7, 2015

I didn't know it didn't have an official name. When I was in elementary school, it was called a "division box", and that's the same name that the math series I teach uses (in another region of the country, interestingly).

9. ### czaczaMultitudinous

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Just for fun I call it the goesinto sign! As in 4 goes into 28 :lol:

However, I teach my kids how problems are set up in different ways and how to navigate through and problem solve regardless of how an equation is set up.

10. ### Ms.BlankCompanion

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Apr 7, 2015

hmy:

Bros, I really don't mean to be offensive here, but someone else asked what I'm thinking...how did you get through a bachelor's program AND and teaching credential program without ever hitting (and fully comprehending) the order of operations? Even if you DID first approach them fully at eighth grade, you've had more than enough time to master the concept. Could this be a component in your troubling job search? Are you teaching something to do with this during demo lessons, have a reference who is telling prospective employers that your math foundation isn't solid, SOMETHING? Just a thought, maybe something to look into... The others are right, the schools I work in are working with the full range of order of operations in fifth grade, with smaller parts of this concept being taught all the way up until then (meaning this is something that you, as an elementary school educator, should be very familiar with...I am NOT saying that just because now they are working with it in elementary, that means you should have learned it in elementary...please don't twist my point around).

Honestly, I'd be furious if I had sixth graders come to my classroom after having a fifth grade teacher that taught them that multiplication MUST come before division and addition MUST come before subtraction...because it doesn't work that way. It would be a LOT of reteaching on my part. Order of operations is a HUGE concept...one that is built upon and used well into high college level math (and the rest of one's math schooling and career). It's important. Without a proper foundation, the kids will suffer greatly.

11. ### MikeTeachesMathDevotee

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Apr 7, 2015

Let x = the cost of the ball
Therefore, x + 1 = the cost of the bat

x + (x + 1) = 1.10
2x + 1 = 1.10
2x = 0.10
x = 0.05

Therefore, the ball costs 5 cents and the bat \$1.05.

My knee-jerk reaction was 10 cents .

12. ### amakayeEnthusiast

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Apr 7, 2015

I also thought 10 cents at first, then realized the bat would be \$1.10. The article was interesting, considering it might be evidence of an aversion to thinking and reasoning to check a problem. That's definitely something I notice in my students...

13. ### czaczaMultitudinous

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Apr 7, 2015

Kids who aren't yet using algebraic thinking could solve this using a guess and check strategy. I guarantee I have at least three kids who could work through the bat and ball problem merely based on perseverance and good number sense.

14. ### a2zMaven

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Apr 7, 2015

They can only do so if they know how to comprehend the question which is a language and/or reading task that depends on a good understanding of grammar.

They have to understand that "a dollar more than the ball" doesn't mean a dollar. Those that don't comprehend language well and don't understand the comparison in that phrase will struggle to be able to do guess and check.

15. ### stephenpeConnoisseur

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Apr 7, 2015

All of our 5th grade teachers are teaching order of operations this year, We spent a lot of time on it. So wasnt my answer actually right with the slash instead of the other sign.

16. ### czaczaMultitudinous

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Read the OP's response to the question regarding the slash. Those of us who teach math basically interpreted the slash as 'divided by'.... But then again, I'd be hard pressed to know the rules to volleyball.

17. ### czaczaMultitudinous

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Apr 7, 2015

I guarantee I have at least 3 in my class who have the background knowledge and skills to solve the bat and ball problem. No doubt.

18. ### ChristyFModerator

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Apr 7, 2015

Wow....I don't view order of operations as life altering. I teach the location of the states, but I don't look down on someone who doesn't know them. By the way, when I was taught order of operations many years ago, I was taught that there was no varying. I completely understand the relationship between multiplication and division as well as adding and subtracting, but I was taught that PEMDAS was carved in stone, no reordering. Every text I taught out of said the same. It's only been in the past 2 or 3 years that I've learned different. I'm sure that means I'm lacking some how, but its not something I can change, so I live without shame. Personally, I have a problem with those type of posts, created to shame those who don't know the answer. I was an honor student in school, graduated college with honors, and continue my learning. Just because I may know some random fact/skill doesn't make me better than someone who doesnt.

19. ### czaczaMultitudinous

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Apr 7, 2015

ELA and math tend to be the tested , and asked about on interviews, subjects ( think standardized tests, assessments and screenings further on in life...where the 50 states are tend to be a bit of a parlor trick or questions Jeopardy, sadly , unless it's your area of expertise/ certification/job requirement)... Regardless of what we think, math and ELA are the 'big' areas in tems of elementary content....in middle school and above, all content areas just become more competitive. Regardless, Schools are looking for teachers who KNOW THEIR SHIP . Basic math operations are not considered a 'random' skill. And if someone wants to teach elementary, they betterhave a firm grasp on the content without having to google the most fundamental skills (PEMDAS being one). Teachers should KNOW what they are required to teach. I know where the counties in my state are because that's what I teach...I'm not required to know the twelve pairs of cranial neves ( I could guess a rough stab at them though)..but in terms of 'whats important' in school, there definitely is an emphasis on the 3 'R's...

And PEMDAS has ALWAYS viewed multiplication/division and addition/subtraction as inverse and equal operations. Without parentheses or other notation if what order to prioritize, inverse operations are threatened in a left to righ following PEMDAS

20. ### ChristyFModerator

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Apr 7, 2015

Everyone is most definitely allowed their own opinion. As I stated, I understand order of operations. However,I think telling someone it could be part of why they can't get a job is over the top. It's one math skill. My point wasn't in debating PEMDAS, nor in discussing "parlor tricks". it was to point out that maybe some perspective should come into play. By the way, in your school, I'm sure I'd be viewed as the fluff teacher; since I spend my day teaching science and social studies. However, at my school, I'm viewed as a valuable member of the staff and those kids do more thinking, problem solving, writing, collaboration, reading informational text etc with me than the ELA teacher. And they will be much more prepared to be well rounded citizens.