If we're speaking in technical terms the teacher is actually wrong in both instances. 5×3 is, "5, three times" and should be 5+5+5. Also, when making a shape such as the array shown, conventional math uses the formula b×h (base times height) meaning 4 is the base (width) and 6 is the height.
@Fluffle Puff, In the words of my old English teacher, "Teachers are some of the biggest bitches you'll ever meet."
As a Calc 2 student I would have done the same.
@Fluffle Puff, it feels like arrays would take longer to do than regular methods.
@Fluffle Puff, actually the second one is understandable because the dimensions of a matrix/array is rows by columns
@Pizzatime, Fair enough. Math be weird, yo.
@Fluffle Puff, what you say is true, and that's why this pic was uploaded.
@Fluffle Puff, it is actually read: 5 times 3, so you should write 5 3s...even though the teacher is a dick. The student clearly understands the multiplications.
@Fluffle Puff, five times three is three five times so she was right for the first part.
@He Shat You Not, Yeah apparently my shoddy New York City elementary school teachers back in the day tought us differently
@Fluffle Puff, the problem is, this kid understands that multiplication is commutative and the teacher doesn't seem to fully understand that order doesn't matter in any of these cases. This is absolutely oppisite of how you teach math... encourage thinking outside the box, encourage reorganizing the way a problem is stated.
@Fluffle Puff, common core is madness
@Fluffle Puff, it's EXACTLY the same equation forwards or backwards. Both ways are correct. There is no reason to dock a point for either way.
@euler pie, "we want you to be special and unique, only exactly like everyone else".
@Fluffle Puff, unless the thought process is to always start with the smallest number. 5 seems easier to work with of course. But yeah.
@frodo from 349, i love how I meant the same thing as u but I get downvoted ...
Its because I'm black.
@Fluffle Puff, if I was taught this crap and then asked down for finding the correct answer a different way I'd leave that class. math is complicated enough without something this trivial. just my opinion.
@Fluffle Puff, obviously both cases are correct. The only reason I can think of for her to count off a point would is if she asked to see both ways and the student didn't follow directions. Still a hard ass teacher but makes a little more since.
@Fluffle Puff, You got the first one right but arrays are mxn or rows by columns.
@Fluffle Puff, elementary teacher. They're the reason we have shjt math in the US. That x = times BS and teaching fractions wrong.., legit hear elementary teachers tell middle school/high school teachers," I don't spend as much time teaching math because I don't like it." Well thanks for helping the downfall of our nation Ms. Cut n Paste.... NOTE: does not apply to all Elementary teachers....
@SchroedingerPussPuss, how do they teach fractions wrong?
@Fluffle Puff, common core math basically ignores all of the technical terms.... There's even more messed up examples but I don't feel like looking for them
@He Shat You Not, indeed dude, I balanced it with an upvote...
@Fluffle Puff, Actually programming languages and higher level math use rows*columns as notation for arrays
@Fluffle Puff, Your first point is wrong. I'm too tired to explain, so try to figure it out why on your own.
@wiseheadlesschicken, That notion has already been established in this comment thread.
@talmet, they are taught as decimals ... Teachers don't understand the material and try to teach what they themselves can't apply--- students don't understand that fractions are so much more and come to fear them because those teaching the subject material fear the subject... It's an ugly cycle. BTW, Legos are an excellent way to teach fractions
@SchroedingerPussPuss, fractions are taught as decimals? How? That doesn't even make sense....
Decimals are fractions. Thats what the decimal places mean....1/10, 1/100, etc...
@Fluffle Puff, happy 100th upvote!
@CellSword, What year is it
And this, ladies and gentlemen, is why Common Core mathematics is a terrible idea...
@The Home Despot, You speak the truth brother/sister/apache!
@The Home Despot, I wouldn't say this is a common core problem, but rather a teacher problem. However, I have attempted to teach a class via common core (and I consider myself good at learning new things as well as a math wiz), and both me, the other teacher, and the whole class was in a collective state of, "what is this crap?!"
@The Home Despot, There's nothing wrong with Common Core, it's just that the execution of it was terrible. Change things drastically with no preparation, there's going to be issues. But Common Core math is just the idea that kids should know *why* math works - foundational skills - rather than just memorizing formulas, and that kids should know more than one way of solving a problem. Both of these are worthwhile goals. Only the execution was flawed, not the intent.
@Ruupasya, EXACTLY!!! Teachers were not properly trained to teach Common Core. The methods are solid but the delivery flawed because the preparation of the educations was inadequate. Very similar to Texas CSCOPE. Was it all bad? No! Actually there are some really great lessons. Was it meant to be a complete curriculum? NO- it was meant to add to a curriculum to enhance it.
@Ruupasya, eh, common core math, at least high school level is pretty horrible.
It was developed by a group of people, only one had any experience teaching students, and only one had a degree in mathematics (and it was the same person in both cases). He voted against the final curriculum, but was over-ruled by everyone else, and had been spending the last several years traveling around the country trying to get people to not use common core math.
His main issue is with the geometry curriculum, which is based on a theory that was created in the 1970s in the USSR. It was tested in the USSR for one year, before they realized it was horrible. It was never used again, until people at common core read about it and were like "that is a great idea!"
@The Home Despot, as a teacher, I cannot agree with you more...
Ok that's just nitpicking.
@DesertHumour, Nah man. It specifically says to use addition to show your work. They didn't
@Hoopscallion, and i read that wrong. Yeah it's nitpicking
Used to get points deducted all the time for not showing my work. I've always done basic math in my head. I got punished for being smart. Took calculus in high school and got a perfect on the math part of my sat's.
Well... It teaches kids to follow a logical progression in the equation
@Mumen Rider , it teaches kids that if they use the commutative principle then they're gonna get points deducted. That's not alright in my book.
@Mumen Rider , depends on how you learned it... and how you understand. If they had made an actual mistake but still wrote rhe correct answer it would be okay but the fact that they did everything just slightly different makes this teacher a bithc
@Mumen Rider , there is no "logical order" in equations. You have to learn how to rearrange/simplify/etc...
@Mumen Rider , ...how does what the student did violate pemdas?
There is nothing in pemdas that says 3*5 doesn't equal 5*3
@talmet, obviously not, that's not the point. The child has to be ready to learn that at some point shjt will stop being interchange all so common core maths try's to give everything a proper order so that once a child starts learning Pemdas it's less of a system shock. There is no logical progression of such an easy equation but they enforce one so that children can understand that there will be a reason to follow the order one day.
@Mumen Rider , so, because some day other operations might not allow an interchange, children are taught that there is one in this case??? That's idiotic.
Sitting on your chair doesn't require a seatbelt, but because someday you'll be sitting in a car, we're going to force you to wear one in every seat.
The point is that they are teaching children that there is only one way to do math problems, while in reality there are almost always numerous ways, and the point is to find whatever path makes the most sense to you.
Teaching children that even though two things are equal, only one is allowed is teaching them a list of idiotic rules that aren't part of actual mathematics.
@Mumen Rider , also, if we are going to go by the rule "because it isn't always true, we should teach kids it's never true." Then the question is wrong.
The symbol used in the problem is "x"
That symbol, when used for multiplication, is exclusively used to denote a cross-product. Therefore because there will come a day where there is a difference between the different symbols used to denote multiplication, we should require students follow that rule always.
You can not take the cross-product of two scalars (numbers), therefore the problem has no answer.
Technically I see the teachers point. I was always taught that you read the multiplication sentence (if you will) as X groups of Y so 5 groups of 3 would be twchnically right under that teaching (and 3 groups of 5 technically wrong)
@TypicalAustralian, incorrect thinking. Just because you were "taught" that way, doesn't make the other way incorrect. The beauty of multiplication or addition... It doesn't matter which order you put them in. 5 groups of 3 = 3 groups of 5.
@big freedom, yes but teachers will mark to how they teach.
@TypicalAustralian, which is why/how we teach to the bottom rather than to the top. Everyone is equal(ly shîtty)
Community property- this teacher needs help
As a computer science major, i can confidently say the norm is to create an array by rows x columns, so the teacher would be right in number two by this logic.
When you're so done with your job.