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Just teach my kid the math

solipsys.co.uk

61–70 of 116 posts

Re: Just teach my kid the math

#61

Earlier quoted context omitted.

> And teachers are trying to teach how to make change? No, the "making change" comment is an example of how these techniques of thinking about numbers do turn up in real life. > I understand “anchoring to fives and tens” but I don’t understand why anyone thinks it’s a good way to do anything except confuse kids. It's a part of a broader strategy to talk about the structure of numbers and the operations on them. > Doe…

I’m a parent and I object not because I don’t understand it — it’s not too difficult to pick up — but because it completely misses the why of math. Being able to mentally estimate numbers or do simple arithmetic is a good skill, but having universal algorithms for solving problems and describing the universe is really what math is more about. I can trace my trajectory into computer science all the way back to practic…

> having universal algorithms for solving problems and describing the universe is really what math is more about.

I'm not sure I understand what you mean. What universal algorithms are there currently for solving problems and describing the universe? And why are these universal algorithms more important than estimation skill in practice?

Are you suggesting that there's always only one true way to do things in math, and that the quest for the one true way is the only noble pursuit?

FWIW, to me that sentence somewhat reads like a pre-conceived idea about math that could possibly impede your appreciation for valid alternative approaches.

It's worth considering that in computing, the algorithms that have been used for math in processors and standard libraries have been changing dramatically ever since the first transistor. And it's not because the newer algorithms are more universal, it's often because we're simply making different tradeoffs over time. Sometimes it's because better algorithms are being invented, because the algorithms we thought were great turn out to be not universal. Sometimes it's because a new fast approximation formula is discovered that is accurate to the precision of the machine.

There's very little in computing today that is "universal", despite the pedagogical emphasis on this abstract idea. There are, however, lots of algorithms that are canonized. Math constructs that seem universal because everyone knows them and they're popular, and alternatives aren't well known, enough that it becomes hard to imagine the alternatives.

> My kids are entirely missing that in their common core education...

Are you absolutely certain that's true? Common core, as the author pointed out, is still required to teach the old algorithms. Are you sure you're not having an emotional reaction to not quite understanding why some of the new methods are there and/or being unfamiliar with them? Your reaction here is exactly what this entire post was addressing.

Re: Just teach my kid the math

#62

Earlier quoted context omitted.

As someone not from the U.S. I wonder, what does "outdated" mean? Can you give a simple example - e.g. comparison - what would be "math back then" and "math nowadays". Because to me math was always just math especially if it comes to numbers.

Here is one potential example from a number of years back. Maybe it counts as "back then." My daughter's algebra teacher was teaching the laws of exponents. When faced with "what is x^0," the teacher gave axiomatic reasoning of "x^0 is always 1. Nobody knows why, you just have to memorize it." When I confronted him about it, his response was along the lines of "we don't have time to get into concepts and teach reason…

>Nobody knows why, you just have to memorize it.

While that's clearly a bad answer, it's not clear that an answer to the effect of: "That's a great question but answering it requires getting into a number of somewhat advanced topics. But if you're interested, here's a good place to start." would be.

Personally, I actually could not tell you the answer myself--although I could look it up.

I agree that, where practical, understanding "why" is preferable. But, even in more advanced subjects, you sometimes just don't have the basics to derive everything from first principles. High school physics is an obvious case when most students haven't had any calculus yet. But even intro courses at a lot of good colleges often ask you to accept certain things as true because understanding why they're true requires significantly more background in the subject.

Re: Just teach my kid the math

#63
> The 21st-century is not looking for humans who serve as calculating machines, but instead it seeks problem-solvers and innovative thinkers.

I distinctly recall how one of my grade school teachers justified learning maths: "In the future, you aren't going to be walking around with calculators in your pocket!" Yet today I routinely check even simple calculations with the calculator in my pocket.

I've found that error-checking is the key to doing 'well' in maths, yet that's something humans are bad at and something machines are great at. Given this, I'd love to see a future where learning to do math strongly emphasized learning how to best leverage computers for error-checking. That's a skill I wish I had developed earlier...

Re: Just teach my kid the math

#64
> We need to communicate the true goal of given exercises to parents.

This is spot-on, and can't be emphasized enough. The goals also need to be communicated multiple times, more clearly to the students, in writing in the homework. So much of the homework asks what seems like trick questions when I look at it. Whenever they weren't paying 100% attention in class, it seems like trick questions to them too. The exercises feel like they intentionally withhold stating the goals clearly for fear that it would give away the answer or fail to make the students struggle enough on their own.

> Make showing/explaining your work interesting.

This is true, but tough. Not every exercise should be an essay answer or story problem. The homework my kids get has lots of variations on exactly the example the author gave, and it doesn't feel like it's helping generate any appreciation for showing the work or for coming up with alternatives. It usually just feels like forced busywork.

My real appreciation for showing my work only came in college physics when I finally realized that I make too many mistakes when I try to think my way through steps. Writing down every minor step was finally more efficient and accurate than not doing it.

Re: Just teach my kid the math

#65

Earlier quoted context omitted.

I’m a parent and I object not because I don’t understand it — it’s not too difficult to pick up — but because it completely misses the why of math. Being able to mentally estimate numbers or do simple arithmetic is a good skill, but having universal algorithms for solving problems and describing the universe is really what math is more about. I can trace my trajectory into computer science all the way back to practic…

Traditional elementary math teaches you algorithms without discussing why they work or the cases where they break down. They seemed arbitrary and untrustworthy. I'm glad that worked out for you, but I don't think many students get the same value.

Part of the problem with this is that I feel elementary school teachers often lack understanding of why the math works. I remember hearing horror stories of people taking the Praxis and all the elementary teachers freaking out about the math -- one even said she had failed that section three times! It doesn't bode well that these are the people teaching our kids how basic math works. And it does show when they get to secondary schools.

Re: Just teach my kid the math

#66

Earlier quoted context omitted.

Learning by rote doesn’t teach you anything.

Are you sure that it doesn't teach you anything? Somehow the students of "old math" were able to put a man on the Moon.

So you're advocating the return of the slide rule? As that's what was used for most calculating, the "old math" method being too cumbersome for such large problems.

Re: Just teach my kid the math

#67

Earlier quoted context omitted.

As a math teacher (Algebra II), I think this would be great. The problem is that most of my students won't go home and watch the videos. Either because they can't (lack of internet access, have to work to help support family, etc.) or are just lazy and won't. I've had to quit giving homework, even to the upper level classes, because nobody would do it. They'd just come in the next day and make excuses and have nothin…

As a former inner city math teacher, I feel you. Getting students to do _anything_ outside the classroom was practically impossible. What worked for me for homework for a little while was having the students do 5 push ups for each day they missed homework in a row. I suddenly was getting 90%+ participation on students completing their homework! It was fantastic until someone told the VP, and the VP asked me if I was…

Exactly! I'm not in an inner-city area, but a rural one and there's a lot of the same problems. The poverty level of the county I teach in is 20%, and a lot of the students have to go home, and often get no support at home. And it's a clear night and day between the ones who do get support and encouragement and those who don't.

Sadly, the biggest issue I see is that they want school to be, basically, training for a job and real life. So, since you'll never solve a system of equation on a job (or so they believe), they don't see why it should be taught. But, yeah, that's not getting into accountability issues with students and their families. It's a frustrating cycle, and is likely going to push me from teaching before too much longer.

Re: Just teach my kid the math

#68

My problem with the "new math" is the lack of volume. Developing a sense for the numbers is best done by working more with numbers; in the "old math" kids had to do thousands of additions in the first and second grade, and developed ten times the sense of numbers compared to kids today. Theory is theory, but practice is practice. Just get over the addition and multiplication, please. That's not where the true math is…

Learning by rote doesn’t teach you anything.

Really? In the case of math, it provides you with the ability to add/multiply/etc. Now, maybe you don't think that being able to do fast and reasonably accurate mental or paper-based arithmetic is important in a world in which calculators are ubiquitous but rote learning does help give you that ability even if you don't understand deeper mathematical concepts.

Asimov's short story "A Feeling of Power" is a fun read by the way.

Rote learning also has a role in things like language vocabulary but in that case there are certainly differing approaches to developing language skills. My understanding is that there's a lot of memorization in things like medicine as well.

Re: Just teach my kid the math

#69
post #41

> We need to be sure not to insist on one approach when analyzing a problem It's encouraging to hear from educators out there who understand communicating the value of problem solving and comprehension is more important than rigid adherence to methodology and procedure. I remember the most useful aspect of my secondary school education (12-16yr) was learning how much I liked problem solving. However I came to this re…

its my understanding that common core math is of the theology that its more important to learn how to think than to solve the question.

its also important to understand that if a kid uses 'the old way' to solve a question, they do not get points for it. remember, this is coming from an ideology that being taught how to think is priority number one, and priority number two is to not deviate from that thinking.

it was always frustrating in hs, especially calculus when I would get 0 points for questions i had right because i used a shortcut, trick, or simply solved it more efficiently. then I got to college and the professor encouraged that. on the first major exam I scored a 96, far above anyone else, and the professor asked to shake my hand, because no one ever solved equations so efficiently before.

i attack and do problems differently, sometimes out of necessity. dyslexia is an adversary of mine, and i find it better not to fight it on its home ground. i also read slow, and take much longer to absorb a problem into my head than other people. but once i do, i own it. unless people make me do it their way in the process. its like running 100m hurdles with 30 hurdles.

im sure you love how you solve problems. you can do it fine your way, i cant. once you start forcing everyone to think one way and evaluating them, your measuring each animal how well they climb a tree.

Re: Just teach my kid the math

#70

Earlier quoted context omitted.

Are you sure that it doesn't teach you anything? Somehow the students of "old math" were able to put a man on the Moon.

So you're advocating the return of the slide rule? As that's what was used for most calculating, the "old math" method being too cumbersome for such large problems.

As someone who actually learned to use a slide rule before pocket calculators became available, that's probably not the best example. Slide rules were good for getting "[EDITED: precise not accurate] enough" results in various situations where they could do so more quickly than solving by hand. You still needed to understand orders of magnitude, precision, and generally having a feel for numbers to use one.

Note also that a lot of calculations on the Apollo program were actually done in part by hand by human "computers." There was even a whole movie about it a couple years ago: https://en.wikipedia.org/wiki/Hidden_Figures

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