My Daughter’s Homework Is Killing Me • Hacker News Board

Re: My Daughter’s Homework Is Killing Me

#131

Post by richardwhiuk » Fri, Sep 20, 2013, 10:15 AM UTC

Tichy wrote: post #82

mike_esspe wrote: post #69

Earlier quoted context omitted.

It just means you should choose a better calculator From my calculator (Genius Mathematical Tool): genius> sqrt(200)*sqrt(200) = 200.0

Well that is also wrong, or at least the .0 shows that the calculator is not doing the equations, it is just calculating. It doesn't know know that sqrt(2) x sqrt(2) = sqrt(2 x 2) = sqrt(2^2) = 2 And that is the kind of thing you get to understand if you do the calculations by hand.

A better way to look at sqrt(2) * sqrt(2) is:

sqrt(2) * sqrt(2) = 2^(0.5) * 2^(0.5) = 2^(0.5+0.5) = 2^1 = 2

Re: My Daughter’s Homework Is Killing Me

#132

Post by mistercow » Fri, Sep 20, 2013, 10:16 AM UTC

comex wrote: post #113

mistercow wrote: post #103

Earlier quoted context omitted.

I have to disagree with this a little bit. The skills you use for mental arithmetic are very similar to the skills for pen and paper. I would view pen and paper as training wheels. It might be argued that mental arithmetic should also at least be taught , but the only way I know of to do that which will tend to generalize to a majority of students is to teach them to use an abacus (seasoned abacus users eventually st…

It's my impression that doing basic mental arithmetic effectively tends to depend on understanding what happens to the magnitudes of numbers after various operations and making good approximations, which has very little resemblance to the brute force long multiplication/addition/division that is taught, but is teachable; yet approximations are almost never acceptable in school, despite being very useful in real life.…

The first thing you described is what is called "Fermi estimation". Basic mental arithmetic is being able to do addition, subtraction, multiplication and division in your head. That kind of arithmetic is strictly a prerequisite for Fermi estimation. The main purpose of Fermi estimation is not to make the calculation easier (although it can be used for that too), but to get answers while not having very good data.

For example, the other day I was trying to figure out, supposing I built a small 4-foot deep swimming pool in an apartment (not on the base floor), if I could expect it to weigh less than what the builders would assume the floor needed to be able to tolerate over that area. I didn't know the mass of a cubic foot of water off the top of my head, so I went off of guessing at how many 2 liter bottles would fit in the volume, and how much a crowd of people would weigh if they all clumped together tightly. Based on these estimations, I knew my answers would be within an order of magnitude of reality. Since the first answer was several orders of magnitude larger than the second answer, I knew that the final answer to my question was "no".

I generally do this kind of thing several times per day, because my brain is filled with crazy ideas like building swimming pools in apartments.

The answers Feynman came to could be done with ordinary mental arithmetic, assuming you have good tools (better than I have) for moving numbers between working memory and short term memory, and the tricks he used to get there faster are shortcuts you simply learn with time and practice.

But basic mental arithmetic is very similar to pen-and-paper arithmetic. The main differences for me are small mechanical adjustments to make use of results that I have cached. For example, if I'm doing division, it might be easier to multiply the number by four first, and then divide by four at the end. And of course if I'm getting a rough estimate, I'll do some rounding here and there to make things more convenient.

The other major difference is that I usually reduce a fraction as far as possible before doing long division, since that makes the multiplication steps (necessary for getting the remainder) simple table look-ups instead of long-multiplication.

But the basics are exactly the same.

Re: My Daughter’s Homework Is Killing Me

#133

Post by tptacek » Fri, Sep 20, 2013, 10:18 AM UTC

acabal wrote: post #19

What stood out for me from this article wasn't the homework load, which only seems slightly more than what I remember from my own youth, but rather that: 1) a teacher can accuse a parent of "cyberbullying" for an email sent in purported confidentiality to others, and that the claim can be taken seriously. Obviously I didn't read the email, but the author seems well-read and reasonable, so I'm inclined to conjecture t…

The "cyber-bullying" thing seemed janky when I read it. We don't know exactly what he wrote to the other parents, or the tone of the conversation they had. We know that one parent was alarmed enough by the conversation to (apparently) forward it to the school administration. It may have been nastier than the author is crediting it for.

Re: My Daughter’s Homework Is Killing Me

#134

Post by flumbaps » Fri, Sep 20, 2013, 10:19 AM UTC

cookiecaper wrote: post #11

rwallace wrote: post #4

There comes a point when an institution becomes so badly broken that the only rational course of action is to get the hell out, and look elsewhere for a solution to your problems. It looks pretty clear from this article that the US school system is well past that point.

Effective schooling could never occur on such a federated level. There's such a broad range of individual personalities and skills along varying axes that the idea of "let's put all the kids born within 10 months of each other in our geographic area in a classroom, and threaten force on people who don't want to cooperate" is never going to function well. I hold the opinion that the proper training and education of on…

>Effective schooling could never occur on such a federated level.

Really? You think that state run education is terrible all over the globe? I don't think the problems with the US system are universal. Certainly here in the UK, education is pretty good. The UK is smaller, but we're only talking a factor of five here.

Asking people to educate their own children is unrealistic. Teaching is not easy. Good teaching requires intelligence, skills, knowledge and understanding that most people don't have. Private tuition requires a lot of money, which most people don't have. You can claim these things are a cop-out, but I think you're being naive. You are a successful high school dropout. Which means you're probably very smart, motivated and independent. Most people are not like you. It's unrealistic to judge other people by your own standards. Most people need education while they are young in order to give them vitally important abstract thinking skills they simply wouldn't be able to figure out on their own. Most people are not capable of providing such an education for their own children. Education has always been a mechanism of control, but that's because most people need to be taught some measure of control. The people that don't need it can think for themselves anyway, so it doesn't matter.

Re: My Daughter’s Homework Is Killing Me

#135

Post by code_duck » Fri, Sep 20, 2013, 10:21 AM UTC

mgkimsal wrote: post #123

code_duck wrote: post #28

My high school in Connecticut declared that you should spend 1 hour doing homework for each academic class every day, which adds up to 12 hours each day focused on attending school, or more. I have no idea why this sounds reasonable to administrators and teachers. The idea of 'memorization' as learning has always bothered me... The most reliable long-term way to recall things is to learn and comprehend them.

Couple of thoughts: There's some things that need to be memorized - basic multiplication tables - I memorized those (9*8, etc). Basic articles/phrases in Spanish. Some basic world/state capitals, etc. But at some point memorization doesn't get you anything any more (except passing a test, maybe) - memorizing a few basic building blocks helps for the larger problems, and eventually the truisms of the building blocks b…

I think the results of multiplication of small integers should be remembered from frequent use, rather than explicitly committed to memory. Acting as if these values are a member of a group that must be memorized like state names, as if they are arbitrary, distances students from understanding that they can easily determine a multiplication result by calculation if they don't know it (or 'remember' it).

I think we might be working from a different idea of what memorization means. I associate it with a truly rote impression of abstract strings with no attempt at comprehension of their meanings individually (as alluded to in the article). I'd think something like Spanish phrases require comprehension to be used.

Definitely one problem was lack of coordination between teachers in the area of homework load; sometimes teachers would arbitrarily declare that we needed to be spending twice as much time on their class for a period of time.

I suppose teachers may think the student workload is reasonable because they have their own. Overall I think that would reflect a lack of understanding that it's improper to expect another person's child's world to be almost entirely composed of your governments school plan. Academically, I learned far more outside of school reading and programming on my own, and in music lessons outside of school. The teacher is being compensated monetarily for their time and that is his or her choice.

Re: My Daughter’s Homework Is Killing Me

#136

Post by tptacek » Fri, Sep 20, 2013, 10:22 AM UTC

vacri wrote: post #35

rtpg wrote: post #27

Earlier quoted context omitted.

I spent a lot of time up until high school forcing myself not to use a calculator, because I wanted to work on my mental skills in arithmetic, but I always make a lot of small mistakes, even now. I have a hard enough time concentrating on 'easy' things , please don't ask me to hold numbers in my brain. I am a pretty "mathy" person but mental multiplication is not meant for the human thought process, too much is going…

To be fair, I don't hold her to be the slightest bit representative, it's just that such a simple mathematical process is just... automatic. I'm not mathy at all - I've abandoned several online crypto intro courses because I can't follow at a reasonable speed when the notation comes out - but when it comes to manipulating single-digit numbers? In her case it was significantly affected by her lack of motivation, but i…

I'm enjoying your comments. Regarding the crypto: that's too bad, because a big chunk of crypto involves de minimis math, and that chunk is the most useful; crypto is as much algorithms and computer science as it is math. Consider letting us beat you over the head with crypto challenges sometime; we wrote them in ASCII text, so there's no notation. :)

Re: My Daughter’s Homework Is Killing Me

#137

Post by tptacek » Fri, Sep 20, 2013, 10:24 AM UTC

GotAnyMegadeth wrote: post #128

tptacek wrote: post #124

Earlier quoted context omitted.

How caustic a lesson to teach your kid, that they should organize to cheat on homework, so they can artificially inflate their grade. I suppose it does set them up for a productive life of investment banking.

I never saw school as a place to learn facts, but as a place to learn how to socialise and how to deal with life. Learning how to get a good grade is important, but only because people think that it represents your worth as an employee. My parents/TV/books/the internet taught me most of what I know.

I am way, way, WAY more concerned about the ethics my kid learns than I am about whether he gets a B or an A in World History.

Re: My Daughter’s Homework Is Killing Me

#138

Post by ja27 » Fri, Sep 20, 2013, 10:25 AM UTC

Afforess wrote: post #39

tudorw wrote: post #26

Six and a half hours sleep, this is way too low, Millpond Children’s Sleep Clinic recommends over nine for a 13yr old. http://www.nhs.uk/Livewell/Childrenssleep/Pages/howmuchsleep...

I once asked a vice principal (way back, 10 yrs ago) why schools started so early when lack of sleep was known to be bad. He said it was so there was time for sports in the evening. If you started at 10 or 11 school would run until 6 and it would start getting dark. Sports are why kids sleep is ruined.

When I drop my daughter off at 6:45 AM (school starts at 7:30), sometimes their football team is out on the field practicing under lights.

Re: My Daughter’s Homework Is Killing Me

#139

Post by tptacek » Fri, Sep 20, 2013, 10:25 AM UTC

tudorw wrote: post #26

Six and a half hours sleep, this is way too low, Millpond Children’s Sleep Clinic recommends over nine for a 13yr old. http://www.nhs.uk/Livewell/Childrenssleep/Pages/howmuchsleep...

I agree and felt bad for the kid. Why is she being allowed to stay up until midnight doing homework?

Re: My Daughter’s Homework Is Killing Me

#140

Post by scotty79 » Fri, Sep 20, 2013, 10:27 AM UTC

acabal wrote: post #19

What stood out for me from this article wasn't the homework load, which only seems slightly more than what I remember from my own youth, but rather that: 1) a teacher can accuse a parent of "cyberbullying" for an email sent in purported confidentiality to others, and that the claim can be taken seriously. Obviously I didn't read the email, but the author seems well-read and reasonable, so I'm inclined to conjecture t…

Especially funny is criterion that makes it cyberbullying:

> the teacher felt threatened

Am I supposed not to sneeze if the person is afraid of loud noises? Am I supposed to say he's doing great job (if he's not) just because he feels insecure there and feels threatened by any critique?

They only reason they were able to pull this of with straight face is because "cyber" becomes to mean "sinister"