One is not prime

[MongoTheGeek]

I once got into an argument with my first grade teacher about gravity on the moon. She insisted that there was none... probably an easier concept for first graders than explaining less gravity but man that irked me....

I also had issues with one of my boss's daughter's geometry teachers. He sent home a problem (which my boss brought to work) which consisted of a parallelogram with various measurements and the object was to find the area of the parallelogram. The only problem was that the vertical height was greater than the length of the parallel sides. The answer he was looking for was a simple trick but I still maintain that the shape could not exist in real space and thus had no answer....

Heavy boots

And Was the height greater than both sets of parallel sides?

I used to try to remember the 355/113 approximation but tended to forget.

But now I just remember pi as 3.1415926535.

3.141592653589... See that rhymes. Easier to remember.

I was once in a room where a dozen people recited pi to 100 digits. One made it to around for 150. Then again, I also had a professor in college say pi is 3, or if you are in a hurry 10.

I am still not sure about 1 not being prime. Its so beautiful if it is prime. Geocities is blocked at work so I can't read the arguments for and against.

One last thought. Pi has been calculated to a bazillion digits. What's the most accurately its ever been measured?

 

[ham_man]

I am still not sure about 1 not being prime. Its so beautiful if it is prime. Geocities is blocked at work so I can't read the arguments for and against.

"In mathematics, a prime number (or a prime) is a natural number that has exactly two (distinct) natural number divisors, which are 1 and the prime number itself." (Wikipedia)

So 1's two factors would be 1 and 1. Ergo, 1 is the only factor.

3's two factors are 3 and 1.

5's two factors are 5 and 1.

Get it...?

 

[CompUser]

Like someone said before, teachers telling us we would use cursive for the rest of eternity. I have not used it in years and before that only because teachers made me.

My sister had a teacher that thought sharks had bones.

I had a geometry teacher this year (9th grade) that didn't understand conservation of energy.


Oh yea and my favorite- "names hurt". No they don't, interpretations hurt. If I called someone named John, John he would not be offended. If I called my friend an a**hole he would not be offended either because he knows I am just playing around.

 

[MongoTheGeek]

"In mathematics, a prime number (or a prime) is a natural number that has exactly two (distinct) natural number divisors, which are 1 and the prime number itself." (Wikipedia)

Get it...?

Definition; I understand the concept.

I guess I don't understand why it was defined that way as opposed to being a number only divisible by one and itself, allowing 1 to be a prime, which from the wiki article seemed to be the original definition.

 

[steamboat26]

I once got into an argument with my kindergarten teacher because she asked what was is space. and i said aliens. and she said no. i still hold my original stance

 

[CubaTBird]

http://primes.utm.edu/notes/faq/one.html

meh..

 

[cait-sith]

Factor prime numbers? Is that really the kind of busy-work they give kids today?

Why would they ask kids to factor prime numbers? The answers for each number would be 1 and the number. That's like asking them to spell a word already written on paper in front of them. Or.. do you mean.. verify that a number is prime? Now that's busy work!

I certainly wasn't impressed with the quality of my teachers until I got to university, and even then.. a lot of things I was required to learn on my own. But in it's own little way, that made me a better-equipped learner. I think eager and interested people will learn no matter who teaches, provided they have a textbook. Less interested people will see the opposite effect.

 

[SC68Cal]

And to think that schools want to standardize curriculum with more expensive textbooks.

 

[Doctor Q]

I used to try to remember the 355/113 approximation but tended to forget. But now I just remember pi as 3.1415926535.

Actually, It would be better to use 3.1415926536, since that's pi's rounded value. But you probably don't need that many digits of precision anyway.

Factor prime numbers? Is that really the kind of busy-work they give kids today?

After they've done a few, they've learned the lesson. Seeing that 2's factors and 1 and 2, 3's factors are 1 and 3, 5's factors are 1 and 5, and a few more, kids get the idea better than if they just hear a definition or listen to the teacher explain it. They don't need to factor many primes, but doing a few is actually helpful.

After that exercise, they were given multiple choice problems to identify the factorizations of composite numbers. That's Lesson 2 and it's a bit harder.

3.141592653589... See that rhymes. Easier to remember.

That too would be better rounded to 3.141592653590, so perhaps you should omit the final zero and use 3.14159265359, because that too rhymes!

 

[commonpeople]

I once stumbled on this equation as a step in a proof:

"zero to the power of zero divided by zero factorial equals one"
(0^0)/0!=1

 

[taytho]

i feel foolish..... i didnt realize that sharks didnt have bones...... thats what i get for living in missouri i guess...... very little shark exposure.

 

[atszyman]

And Was the height greater than both sets of parallel sides?

Side lengths were something like 4 and 8. The height measured perpedicular to the 8 unit side to the other 8 unit side was something like 12.

The basic trick was to realize that the area was 8*12 because if you "clip" the right triangle formed with a hypotenuse of 4 you can create a rectangle with a side length of 8 and height of 12.

Unfortunately 1) I did not see the trick and had a lot more geometry fun 2) this requires a right triangle with a side that is longer than the hypotenuse, an impossibility with only real numbers....

I always wanted the boss's daughter to argue it with the teacher, sadly I don't think it ever happened...

 

[MongoTheGeek]

i feel foolish..... i didnt realize that sharks didnt have bones...... thats what i get for living in missouri i guess...... very little shark exposure.

There are two types of fish. Bony fish, and ummm... hmm other fish. Sharks, rays are cartilaginous fish. They have internal support structure but its not rigid.

I once stumbled on this equation as a step in a proof:

"zero to the power of zero divided by zero factorial equals one"
(0^0)/0!=1

Never mind that factorial is only defined for natural numbers, and 0^0 is undefined.

That too would be better rounded to 3.141592653590, so perhaps you should omit the final zero and use 3.14159265359, because that too rhymes!

I know the next two digits are 67 which means that yes it rounds up to that, but it blows the meter.

http://primes.utm.edu/notes/faq/one.html

meh..

So it really comes down to "because we said so." The math on the Mersenne Primes seemed to work and allow 1 to be prime and perfect.

 

[Timepass]

I once stumbled on this equation as a step in a proof:

"zero to the power of zero divided by zero factorial equals one"
(0^0)/0!=1

that because anything raise to the 1 power is 1. and 0! is 1. you just divided 1/1

Both of those just happen to be one of the math rules that you just have to accepted. Do they make since no. But they are the rules. 0! is 1 (I used it before in stats.) Those things are just math rules that you have to accepted.

 

[Veldek]

that because anything raise to the 1 power is 1. and 0! is 1. you just divided 1/1

Both of those just happen to be one of the math rules that you just have to accepted. Do they make since no. But they are the rules. 0! is 1 (I used it before in stats.) Those things are just math rules that you have to accepted.

Well, but 0^0 is undefined. You can see this easily: 0^0 = 0^(1-1) = 0^1 / 0^1 = 0/0 = undefined.

 

[MongoTheGeek]

Well, but 0^0 is undefined. You can see this easily: 0^0 = 0^(1-1) = 0^1 / 0^1 = 0/0 = undefined.

Alternatively you could say

lim (x-->0) x^0 = 1
but...
lim (x-->0) 0^x = 0

 

[Josh]

I once heard of a church that taught the young children that dinosaurs were not real, just made up stories (since the earth was only "6 thousand years old" and things millions of years old couldn't be real.

 

[UKnjb]

There are two types of fish. Bony fish, and ummm... hmm other fish. Sharks, rays are cartilaginous fish. They have internal support structure but its not rigid.

The fish with skeletons of bone are called Teleosts and the ones with skeletons made of cartilage are Elasmobranchs.

 

[jaydub]

"I think your wrong..."

"No, you're wrong."

haha I liked this part.

My wife is a second grade (soon to be moving to fourth grade) teacher and she is very aware of what she teaches kids. Unfortunately, some of her co-workers are not as conscientious and have taught the kids incorrect information. Hell, I've even seen it done in my college career by professors who thought the students wouldn't be as well-informed as they are. He gave an example which was proven to be false but he continued to use it throughout the semester.

 

[Josh]

There are two types of fish. Bony fish, and ummm... hmm other fish. Sharks, rays are cartilaginous fish. They have internal support structure but its not rigid.

Chondrichthyes are the cartalidge fishes, such as sharks.

Ostichthyes are the boney fish.

 

[whooleytoo]

This is quite a bit off-topic, but still on the subject of the teacher-student relationship.

Does anyone remember the story, frequently emailed around (probably an urban legend) of a student in an exam; who was set a question. I don't remember the details, but I believe it was something like "You're standing on a building, whose height you don't know; with a metre stick and a length of rope. How do you measure the height of the building?"

He gave a short, glib answer which the examiner wasn't happy with, and so approached the student afterwards. The student then replied he had been bored with the question, but to prove himself he proceeded to rattle off several laterally-thinking methods of measuring the building.

"And the examiner gave him an A".

Does anyone know this story?

 

[tbrinkma]

On the subject of proving teachers wrong...

In my sophmore year of college, I had a friendly dispute with my physics prof about the nature of photons. The argument basically, consisted of a disagreement on whether or not it was possible to have a stationary photon. He insisted it was not possible, I opined that it was. The reasoning I used is as follows.

A photon has the properties of matter, including momentum. You can move things by shining a beam of light onto them. (Check out solar sails for more info.) That means you can transfer momentum from the photon to other object.If you bounce a tennis ball off a wall, it will actually stop completely for an instant. Therefore, if you bounce a photon off a surface, it will stop completely for an instant. (Yes, the logic is sound, no the physics isn't, but then again this was an astronomy class.)

Years later, I stumbled across an article discussing a scientific experiment where researchers had actually managed to stop a photon. Unfortunately, I no longer remembered my prof's email address by that point, so I couldn't send him the article and gloat.

 

[atszyman]

This is quite a bit off-topic, but still on the subject of the teacher-student relationship.

Does anyone remember the story, frequently emailed around (probably an urban legend) of a student in an exam; who was set a question. I don't remember the details, but I believe it was something like "You're standing on a building, whose height you don't know; with a metre stick and a length of rope. How do you measure the height of the building?"

He gave a short, glib answer which the examiner wasn't happy with, and so approached the student afterwards. The student then replied he had been bored with the question, but to prove himself he proceeded to rattle off several laterally-thinking methods of measuring the building.

"And the examiner gave him an A".

Does anyone know this story?

Snopes is great. link.

The legend has a barometer instead of a meter stick, and there are a couple variations on the provided link.

 

[Timepass]

Well, but 0^0 is undefined. You can see this easily: 0^0 = 0^(1-1) = 0^1 / 0^1 = 0/0 = undefined.

No it not. that where you are wrong.
Anything raise to the power of 0 is 1.

also 0!= 1

Those are just random math properties. logicly do that make since no but that does not change the fact that they are true.

0^0/0!=1/1 =1

reason 0!=1 is there is a lot of stuff in statitics that would not work unless that was the case since you would be trying to divide by 0. And anything raised to power of 0 just = 1.

Both are just properties that are true. You cannt prove them wrong since you still break down to 0^0=1 and 0!=1. 0 has a lot of weird rules on it that you dont really learn about until upper leval math (pass calucus).

 

[whooleytoo]

Snopes is great. link.

The legend has a barometer instead of a meter stick, and there are a couple variations on the provided link.

Many thanks!! I hadn't read the story in quite a while, and couldn't recall the details.