Many elementary teachers don’t understand math, and it makes them anxious • Hacker News Board

Re: Many elementary teachers don’t understand math, and it makes them anxious

#61

Post by chrisseaton » Sat, Nov 30, 2019, 5:33 AM UTC

dboreham wrote: post #46

chrisseaton wrote: post #33

Earlier quoted context omitted.

I have no intuitive understanding or mental model of the algorithm. I could follow the instructions if they’re written in front of me but I have never managed to understand why they work or to memorise them. I have a similar mental block for standard deviation - I always seem to have another ‘but why?’ question that eventually people answer with ‘because!’ and then we’ve both given up.

Try this? https://web.stanford.edu/class/ee486/doc/chap5.pdf Edit: standard deviation is just a fancy name for root mean squared over the sample offsets. The square is there to deal with the fact that there are positive and negative offsets. The mean is the whole point of the exercise, and the root is to negate the fact that we squared earlier.

But why not use the abs function or operator rather than squaring and rooting?

This is how I always find maths and particularly statistics - I always just want to answer ‘but why’ and then people lose interest in explaining after a while.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#62

Post by Gunax » Sat, Nov 30, 2019, 5:34 AM UTC

rahuldottech wrote: post #53

Huh. I'm from India, and from what I can tell, maths is taught much better here than in the US, at least till 10th grade, after which it's no longer compulsory. It's actually taught in a very intuitive manner, and most students "get" it quite well. Edit: the textbooks are freely available on the web, if anyone wishes to take a look. Look up "NCERT class 10 maths textbook".

Im my experience there is so much variation between countries, between different regions within the same country, between schools within the same region, between teachers within the same school and even students' subjective experiences within the same classroom that I am generally skeptical of broad conclusions drawn between countries like that.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#63

Post by pjscott » Sat, Nov 30, 2019, 5:35 AM UTC

analog31 wrote: post #14

alfiedotwtf wrote: post #3

On the flipside, I was in a Calculus lecture at uni and turned to the girl next to me who was crying. I asked her if she was ok, and she said she didn't understand why she had to sit in the lecture learning Laplace transforms when she "only wanted to be a primary school teacher". From the sounds of it, it was a prerequisite? Edit: Oh :) I just worked it out - I was taught to fold the subtraction and carry right in on…

Seems unlikely, though it may vary from one country to another. Here in the states, you would probably need to take a year of math, but there are levels of math "below" calculus that you can take to get a K-12 general education certificate. Also in the states, engineering students ask the same question about Laplace transforms. ;-)

> Also in the states, engineering students ask the same question about Laplace transforms. ;-)

Laplace transforms are wonderful because they protect you from the differential equations that would otherwise await you if were foolish enough to take a step outside the S-domain.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#64

Post by _bxg1 » Sat, Nov 30, 2019, 5:37 AM UTC

buzzkillington wrote: post #59

_bxg1 wrote: post #26

Earlier quoted context omitted.

Thing is, even now I find it useless. I can do nearly any division in my head whose digits themselves fit in my head (Miller's Law). For anything bigger, I have a pocket supercomputer with me at all times. You're right that it could be a fun programming exercise, though

If you do code in any capacity not being able to understand long division is a huge red flag. In terms of difficulty it's somewhere between regex and being able to write a recursive function.

I didn't understand why it worked (a comment here pointed out that it's just division-by-repeated-subtraction which does make sense now). But I was still able to perform it, during the time when it was relevant to my life.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#65

Post by tmh88j » Sat, Nov 30, 2019, 5:37 AM UTC

alfiedotwtf wrote: post #3

On the flipside, I was in a Calculus lecture at uni and turned to the girl next to me who was crying. I asked her if she was ok, and she said she didn't understand why she had to sit in the lecture learning Laplace transforms when she "only wanted to be a primary school teacher". From the sounds of it, it was a prerequisite? Edit: Oh :) I just worked it out - I was taught to fold the subtraction and carry right in on…

>I asked her if she was ok, and she said she didn't understand why she had to sit in the lecture learning Laplace transforms when she "only wanted to be a primary school teacher"

What university did you attend that Laplace transforms were part of the standard calculus curriculum, let alone a requirement for primary school teachers? From my experience in the US, universities typically offer different sets of calculus classes based on the major. Undergrads in business school might have to take a simplified calculus class or two, but the content is not as in depth as the calculus classes required for STEM majors. I learned about them in a signal processing class, not from the math department. I can't think of a single reason why a primary school teacher should have to study them.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#66

Post by paganel » Sat, Nov 30, 2019, 5:41 AM UTC

protomyth wrote: post #31

alfiedotwtf wrote: post #3

On the flipside, I was in a Calculus lecture at uni and turned to the girl next to me who was crying. I asked her if she was ok, and she said she didn't understand why she had to sit in the lecture learning Laplace transforms when she "only wanted to be a primary school teacher". From the sounds of it, it was a prerequisite? Edit: Oh :) I just worked it out - I was taught to fold the subtraction and carry right in on…

My response to primary school teachers is that they need some mastery of math so they are not anxious about the subject in front of students. Because if the girls in her class lookup to her and she is anxious, nervous, or dismissive of math then those girls will not go into any STEM field. If you want more females in STEM careers then it starts with elementary school teachers loving STEM.

Primary school maths is not really maths, is arithmetics, asking a primary school teacher to go into some crazy higher-maths details in order to teach arithmetics is just a huge waste of resources.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#67

Post by Gunax » Sat, Nov 30, 2019, 5:50 AM UTC

alfiedotwtf wrote: post #3

On the flipside, I was in a Calculus lecture at uni and turned to the girl next to me who was crying. I asked her if she was ok, and she said she didn't understand why she had to sit in the lecture learning Laplace transforms when she "only wanted to be a primary school teacher". From the sounds of it, it was a prerequisite? Edit: Oh :) I just worked it out - I was taught to fold the subtraction and carry right in on…

There seems to be a culture of proud ignorance around math more-so than other subjects. While I am sure there is some engineering student out there griping about having to take a psychology course, they don't seem to complain as much as when non-mathy people have to study math.

I think it is a mistake for our education system to treat math as something superfluous and abstract from daily life. While neither Laplace transforms nor Shakespearen analysis are necessary to live, the former is probably more useful than the latter.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#68

Post by LegitGandalf » Sat, Nov 30, 2019, 5:52 AM UTC

_bxg1 wrote: post #50

aaron695 wrote: post #38

This is because of a lack of men in elementary schools, interesting they skipped the reason. But this is not solvable in the West I guess, it will continue to decrease. Need to offshore it. IE. Produce good external lesson plans that are free to use.

...yikes.

Ha,I see why you flipped an exception on my comment now. Let me assure you that I'm not attributing the decline of Western Civilization to women teaching math!

Did you read that Chicago study? I'm interested to see if your view shifted any.

Re: Many elementary teachers don’t understand math, and it makes them anxious

#69

Post by tmh88j » Sat, Nov 30, 2019, 6:04 AM UTC

optimiz3 wrote: post #18

Routinely we have to explain to users in a crypto related business that 0.00835 Satoshis is the same as 0.008350 Satoshis. Adult humans don't handle decimals.

That reminds me of A&W killing off the 1/3 lb burger from their menu because people didn't realize it's more than a 1/4 pound and thought they were getting ripped off.

https://www.mentalfloss.com/article/76144/why-no-one-wanted-...

Re: Many elementary teachers don’t understand math, and it makes them anxious

#70

Post by Gunax » Sat, Nov 30, 2019, 6:05 AM UTC

This is a consequence of refusing to acknowledge math as a required course. Teachers and schools loathe to fail a student--especially one who is actually displaying effort and is otherwise a good student.

My high school had an elaborate system of ways for people to avoid doing math. Even though Algebra was technically required to graduate, there were enough loopholes and alternative classes that students could effectively skip learning actual math. Fail an exam? The teacher would give extra credit: presenting about a famous mathematician--certainly interesting work, but does not really show that the student actually understands the core math material.

This is how you get incoming first-year undergrads who don't know how to reduce fractions even though their curriculum indicates they should have learned it multiple times over. They have managed to avoid jumping through the hoop so many times because we gave them a rope to skip instead.