skysight-inc/HackerNews huggingface dataset:
Ask HN: Common Core Math, Better? Or Worse?
What do you think of common core math? I'm not a fan of common core at all, but I love how it teaches math. Instead of counting by ones, or doing crazy right to left carry the 1 nonsense it concentrates on going left to right.

For example, normally 14 + 17 would be:

7+4=11 -> Put the 1 in the ones place to "carry" it -> 1+1=2, plus your carried 1 = 3 -> Answer: 31

At higher levels it becomes harder to do math in your head with this foundation and students are more likely to depend on slow paper methods or calculators.

With common core 14 + 17 is:

(Tens place) 10 + 10 = 20 -> (Ones place) 7+4 = 6+4+1 = 10+1 = 11 -> 20 + 11 = 31.

This can indeed be harder to learn when on paper, but with the help of a teacher this is incredibly easy, and very fast. Most of you are probably already doing this in your head, and you probably taught it to yourself because what you learned in school is slow and taxes your personal RAM.

I don't get all the up and arms about it. As I understand it, this is how Asian countries do math (based on the abacus). When you look at the statistics, US schools do better at lower levels but cliff dives when it comes to middle school and beyond.

Some links:

Khan Academy: https://www.khanacademy.org/commoncore

Google Image Search for 'common core math': https://www.google.com/search?q=common+core+math&newwindow=1&safe=off&es_sm=122&qscrl=1&source=lnms&tbm=isch&sa=X&ei=TusQVMn3Bo62yATlnoH4CQ&ved=0CAkQ_AUoAg&biw=1920&bih=965
“Violating the GPL is not a big deal”
I realise Jobs needed a push to get to the open app system, and was originally against it - or at least for something that was more like the Widget system on OS X, and not so much like the Objective-C monster the App Store turned into.

But my point - which apparently no one understands here - is that the products were always conceived originally, from the top, as part of a strategy that included a stack of support services and interactions with a user community.

I'm not seeing that on offer here.

Of course WATCH does apps. That was always a given. But the App Store is saturated, and once devs have produced the obligatory new watch faces, fitness, dating and friend-finding apps, my guess is that the opportunities for doing something compelling, original and gotta-have-that are smaller than they were with the original iPhone.

There will be an exception, or maybe four or five. There will not be thousands of potential gotta-have-that apps to match those that are available in the iPhone/iPad app store.

Apple has always been one of the few tech companies that understands that you don't sell hardware, or software - you sell a complete package of unique and exclusive benefits that happens to run on a hardware device.

That worked for the original Mac, then the OS X Mac, then the iPod, then the iPhone, then the iPad. All had obvious user benefits that were so intuitively compelling they barely needed explanation, and which were enhanced and supported over time with software services that made the package even stronger.

I'd be interested to know what the downvoters on this thread believe is the equivalent user benefit and software support package for WATCH.

I don't believe 'It does apps too and there's even an API, so therefore there's an ecosystem' is the most insightful answer to that question, or that it's what users are looking for to persuade them this is a must-have device.
The latest health scare is that sitting causes all kinds of trouble. Expect articles in 10 years saying it was all a lie.
Patreon is on my radar. I'm really excited about the idea of micropatronage, or just patronage in general. I think it's a workable idea but it needs a certain amount of critical mass before it can swing culture enough to be self-sustaining.
Are you racist if you aren't physically attracted to someone? I hope not.
Sketching for UX design
Caml Trading – Experiences with OCaml on Wall Street [video]
Thanks for the recommendation! Bought.

Probably more than 50% of the books I buy come from recommendations on HN, and I've been rarely disappointed.
That's nice of them...
The industry isn't thriving, but music is.

I think what you see is that more and more musicians do it for mainly non-financial incentives. That's been true for most musicians since time immemorial, but it's even more true today.

It turns out you don't really need to pay people much to get them to make and play music. They just need some gear and enough free time to do it.
> since nobody's paying for it the content is usually average at best.

I think that's an oversimplification.

I believe the lack of publishing gatekeepers means the bottom end of the bell curve isn't being truncated. The variation in quality has certainly gone up, but I'm not sure if the mean or median have really moved.

Sure, there's a lot of crap to wade through, but there are also a lot of talented people who wouldn't have been able to find an audience going through old publishing systems.
The orignal study that caused the salt scare didn't claim that increased salt intake caused increased blood pressure. The claim was that a sodium intake on the high end of regular sodium intake was closely correlated with increased mortality rates in heart attack victims. There was no claim made about sodium intake and blood pressure, nor was there a claim about sodium intake and heart attack rates.

This is why I hate the intersection of journalism, science, and the public.
An Introduction to Pry, a Ruby REPL
No, a full day just isn't enough. What about the time when you come home wasted from too much work/partying and you just forget to charge the thing. Then you wake up, decide you don't want to wear it because you just want to chill on the beach/park/anywhere, and then you put it on on the next day, and it is dead. And to use it you need to charge it for an hour or so, so you can't wear it on that day.
> Except that energy burned is not by any means a 1:1 correlation with exercised performed. We are inefficient machines, and our efficiency characteristics vary wildly in ways we don't fully understand.

Your basal metabolic rate is not much different from the guy next to you of similar age and weight, barring some extremely rare circumstance. I don't know what to tell you, other than that.

> Two people consuming the same quantity of energy and exerting the same number of joules on exercise equipment do not see identical or even necessarily related physiological effects. There are many, many factors - other nutrients, genetics, timing, the distribution of work over time (short intense exercise vs. long less intense exercise, etc.) and they all matter.

Exercise is probably the least important part in proper weight maintenance, because of all the reasons you listed. Most people promoting the 'calories calories calories' mantra will tell you the exact same thing.

Your diet, and specifically how much you're consuming (regardless of carbs/fats/salt/etc.) is critical, the rest is secondary.

> There are skinny people who have never been inside a gym. There are fat people who work harder than you. Obviously you can still influence your outcomes, but "energy out >= energy in" is a gross oversimplification.

Not really. Those skinny people are eating less (in aggregate) than the fat people, again barring some very rare metabolic condition. Guaranteed.
Http://www.addthis.com/bookmark.php?v=250&username=vipman
We partnered with Timex on a wearables project once, and their sentiment seemed to be that you needed a couple of thousand SKUs before you'd truly satisfy people's desire for personal expression. With less you'd run into "I like that thin blue band, but it should be a different shade of blue."
Apple makes Android watches, now?
Yeah, but I think "watch fans" are quite different than photographers in that respect.

Watch fans are generally pretty up-front about the fact that they like watches mainly because they're beautiful/elegant/cool artifacts. As long as a watch keeps OK time, they don't seem particularly concerned with the nominal functionality.

I think in reality, many people like cameras for similar reasons, but it's not quite as acceptable to admit that. Even if someone really bought that expensive Leica because it's a beautiful jewel of precision manufacturing and high-quality materials (a perfectly fine reason if you ask me), they often put up something of a front, trying to emphasize all the ways it takes great pictures and helps their photography style...
Quality isn't a linear metric.

Immediacy and media quantity have shot up, like you say. It's one of the most amazing things about living in the world today.

Depth and investigation has suffered, and I think accuracy and objectivity have too. Not every story can be revealed with cell cameras in the right place at the right time. Sometimes you have to dig and dig hard.
I think one factor they forgot to add is culture.

When you're firmly entrenched in a specific cultural background, often it can be difficult to relate to someone who grew up in a different culture.

That being said, I'm white, married to a Caribbean woman (who herself is mixed though very dark skinned). Her family still drives me insane though. To say there are cultural differences would be a major understatement... And things I consider normal behaviour are often perplexing to them as well.
This is what I did with angular-cache.
Right, they paid the guy to write about how Apple's new product has no emotion. I wonder how much you have to pay for that?
Ah! I see now. Thank you very much for explaining that.
Can you think of a single example that:

1) Posits new conjectures
2) Proves those conjectures
3) Those conjectures can be used to formulate new conjectures that conform to items 1-3?

I've read a great deal of smalltalk literature, and I can't recall any papers that would qualify. There's plenty of empirical exploration of ambiguous hypothesis, but nothing that actually provides anyone in the field anything on which they could actually build.
> Well I think that if the length of the fragment is larger than the repeated fragment, you can get a good idea of the number of repetitions.

How?
I live in a country where cycling is a major mode of transportation (Netherlands). I also work (albeit tangentially, this is not an appeal to authority) in transportation planning.

In my view, expectations of cyclists in countries that don't traditionally have bikes on their roads are unrealistic in their expectations. Nobody in their right mind in the Netherlands would ride a bike on highways or major multiple-lane roads (and in fact, it's mostly prohibited); yet I see cyclists in New Zealand and Australia do that all the time (I suspect it's similar in the US but I haven't observed it personally). Similarly, nobody in their right mind drives a bike the same way they drive a car - on the same lanes, in the middle of the lane, basically like a slow motor cycle (outside of areas where cars move faster than walking speed, that is - i.e. not rush hour in urban centers).

Now I understand that you'd sort of have to if there is no alternative, like a well developed separate cycling network as we have. Heck, just having bicycle lanes already seems to be hailed as a big progression in many places. But I have a hard time understanding why cyclists are so determined to portray themselves as this sub-group, a minority that deserves special attention, with its own clothing ranges and gear sets and entitlements and internet forums for circle jerking about how much better the world would be if only everybody else was just like you. I'm trying hard not to blame the victim here, but the problem the author identifies with cyclists turning public opinion against them is real (which is still not a reason not to prosecute people who kill cyclists, of course).

'Our' cyclists (sorry if this sounds condescending, I can't really think of a better way of putting it) don't identify as 'cyclists'. They're just a cross section of the population, and as such there is no such culture clash. Maybe it's easy for me to say because we never had to make a transition the way many countries will have to, but pitting yourself as the underdog who needs special treatment from everybody else seems to be a long, hard slog, or maybe even counter-productive in at least the short term. Not that I have an alternative though, prisoner's dilemma and all.
This is likely caused by the age difference, and the fact that they probably have some overlapping friends, even if it's not just one another. I'd have to guess the way it works is that Facebook looks at the poster, the poster's friends, and maybe the poster's friends of friends for a decent match among them when it encounters an untagged person. He probably scored higher because he does look like her, and those pictures are quite old and lack features that his mother currently has, such as wrinkles.
Which is kind of a funny way for Uber to say "we don't do tipping."

I mean, I guess you could say that my salary "includes a tip," and that it's really 20% lower but then there's a 20% tip on top of that, but obviously I wouldn't actually say that.

Uber says that their fare "includes a tip" because people are used to tipping cabbies. But tips are only tips when they are optional amounts that customers can vary the size of.

I don't think that rides-for-hire should really be a tipping industry anyhow.
IMHO the law should force people to accept such a hindrance, lest we live in a society where those less fortunate or less able are forced to accept all the hindrances instead. Society seems to agree with me -- we do in fact have laws requiring such "hindrances" as accepting service animals: http://www.dol.gov/dol/topic/disability/ada.htm
I love that people say that sitting for a day is as bad as smoking a cigarette.
Depends on your motivations and what you want to get out of it.

For example, for me, it's a great time to be a writer. I wrote a book that I'm self-publishing. If I couldn't do that, I would have had to compromise it in ways I don't really like in order to please a publisher.

I probably won't be making as much money (not that I would make much with a traditional publisher), but that's OK. I'm lucky enough to have a decent-paying day job.

The way writing works today is perfectly attuned to what I want to get out of it.
With the apple watch coming into the market. It'll be very interesting to see what schools do... Currently iPods / cellphones are ban in most schools. If it's seen, kids are typically given a warning. If they repeatedly fail to follow procedures, the device gets taken away. Watches will become a lot harder to regulate.
I've been driving for 23 years in about as many countries with not a single traffic accident (though I'll admit to a couple speeding tickets). I've driven in weather, climates and conditions as varied as polar winter conditions to mountains and desert.

I have something over a million road miles under my belt which puts me at near 20,000 hours of on the road driving experience in mixes of cities to extreme rural environments. I feel comfortable saying I'm a driving expert and that I'm a very safe driver.

I've never felt safe sharing pavement with a cyclist. Ever. Not for my own personal safety, or because of some dubious legal requirement, but for the safety of the cyclist. If you think that makes me sound like some kind of wild west psychopathic car driver hellbent on a Death Race high score spree I suggest you rethink that.

The law also puts requirements on bike riders when using public roads. It's not an unburdened responsibility. However, bicyclists would like to make it a responsibility of car drivers only (as the comments in this thread pretty clearly indicate), and have an unlimited right to use infrastructure that wasn't designed or built with them in mind. However, enforcement of those laws on bicyclists is virtually nonexistent.

The reason I feel unsafe around cyclists is that not only am I operating a complex, multi-thousand pound machine that can take me to triple digit speeds in under a minute, but because cyclists don't seem to be aware that I'm doing involved in that operation. They'll routinely swerve out into traffic, cut across busy intersections and otherwise behave like all the world revolves around them.

Not all cyclists are like this. But I'm hard pressed to find many that observe even some fraction of the laws they're supposed to follow.
If you take in 500 calories per day and burn 1600, that will fit the "energy burned needs to be >= energy taken in" rule, but you'll still die. Even that basic question is more complicated than you're making it out to be.

I feel like you're trying to grind some axe relating to weight loss here, but in doing so you are obviously oversimplifying the field of nutrition.
I don't know. That's kind of what I'm asking. Is preference racist? Or are we scared to affirm that it might be?
Apple wins on hardware, loses on software.
Whenever I get into a taxi who is using a GPS unit, I get really scared. They seem to be new drivers who spend more time looking at the screen than the road, which is not good in Beijing.

But I have the feeling that Watch is not meant for driving situations :) It could be quite good while walking around a new city.
> Some people have $0 and literally can't afford anything

Did you just find that out? Congratulations.

Most of cyclists in NYC are probably making more than you. Save your tears.

If you really cared and understood the dynamics of the 'poor' you would realize that stuff like this is there to protect them.

Rich person can afford the expense of two broken legs. Poor person? Not so much.
In most jurisdictions, laws do typically require seeing-eye dogs to be exempted from "no pets" / "no animals" requirements, with some exceptions.
I agree dropout is awesome. Buddies? :)
yuk. this is the sort of issue that should be solved at the level of the OS, not for every app.

*nix is pretty much "the" cmdline people refer to, and the unix cmdline was well established and in use at microsoft when microsoft created DOS and broke it to shit. No reason to retrofit the breakage backward.

plenty of unix tools don't say anything when you run them with no args, and they're not supposed to, "we" like it that way.

If you have a GUI that can't handle cmdline executables, how about distinguish GUI executables from cmdliners. don't foul the cmdline space with cruft, cruft that works in one context but not in many others. You are explicitly testing to see if you are a descendent of a specific program?
Ask HN: Is Instructor's manual for SICP worthwhile?+
I started a study group to do SICP; while I've done SICP part to part, I've never actually finished it cover-to-cover. Also, I've found the best method of learning has been by explaining to others.

While I've seen many discussions on the SICP itself, I haven't yet found a discussion for the instructor's manual.

The text of SICP I could find online, but the website tells of the existence of instructor's manual. For my purpose, is it worthwhile? It would be good if I could find a HTML version for it, like the original text.

What exactly does the instructor's manual contain? Just the answers and more exercises(and the answers for them)?
...What?

I was replying to a comment saying that cyclists can kill people on the road by causing accidents. I responded by saying that I can't figure out that could happen without the driver being at fault, with the exception of the cyclist getting himself killed.

I'm well aware of drivers killing cyclists and getting away with it. That's not what I was talking about.
> Very long term, energy burned will be == energy taken in.

Not really, unless we're counting death. Most people gain weight as they get older.

> If that's consistently out of balance by... say 100 Kcal/day, that's 0.2 lb/week every week or 10 lb/year or 100 lb/decade. How many 50-year-olds do you know who are 300 pounds heavier (or lighter) than they were at 20?

You're phrasing that the wrong way. Your BMR changes depending on your current weight. If you weigh 180 pounds at 20 and you eat 2700 calories a day, eventually you'll reach a point where 2700 calories is what you require to maintain your body weight (probably somewhere in the 220-240 lb range).

To gain 300 pounds over 30 years would require you to constantly be consuming more and more as time goes on.

You're also completely negating the fact that most people would (and probably do) have a 'reality check' once they get into the 200+ range, and reduce their caloric intake (though unfortunately most likely only to resume their high caloric intake once they've dropped in weight a little).
Siftnet. The World's Time Network
Does this control for factors like age? For example perhaps people of some races/cultures are more likely to marry early (perhaps because of religion etc) so the people who end up using dating sites from that race are more likely to be divorcees (so older) or the sort who were passed over in real life.
While I don't think it's a great solution (give up my vacation time to do more work?!?) I'm surprised so many people think this only plays to the employer's advantage. I've been in a number of interviews where the potential employer has lied through their teeth about what they do and how they do it and even stupidly accepted an offer as a result of one. Going through this process there would've saved me the miserable few months before I had to resign.
Many people say yes it is racist:

http://www.slate.com/articles/news_and_politics/politics/2014/04/okcupid_and_race_is_it_racist_to_date_only_people_of_your_own_race.html
http://www.racialicious.com/2009/10/09/of-okcupid-and-denials-of-racism/
http://everydayfeminism.com/2013/11/racial-preferences-are-racist/
http://www.rolereboot.org/sex-and-relationships/details/2013-11-if-you-wont-date-people-of-a-certain-race-youre-raci

In some cases it is only yes if you are white.
I think the consequences of the injustices are highly asymmetric and that skews people's sense of what is right and wrong.

Cyclists tend to pay with their bodies or their lives when something goes wrong in the street. Drivers -- at least when cyclists are involved -- do not. And often they do not get prosecuted at all. Please read the article linked, it has several examples. I can find plenty more if you like.

If a driver suffers a 30 second delay when a cyclist does something stupid but a cyclist suffers death when a driver does something stupid it's not entirely unreasonable to discount the injustice that drivers suffer at the hands of cyclists.

Furthermore you allude to "sidewalks" as something that cyclists can do wrong. I disagree. Few states have laws prohibiting sidewalk riding though some cities have passed laws against it.

http://blogs.findlaw.com/law_and_life/2013/08/legal-to-ride-...

I couldn't agree more that the best protection a driver has is a dashcam. Just the threat to the other party (driver, cyclist, pedestrian) that such a thing exists might well convince them to not pursue a frivolous claim.
npm gives you dependency hell in a medium sized project, with a node_modules folder 10 times larger than the project.

This on a OS level ... interesting