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Electric misconceptions

This is a fairly big question, and is divided into three parts. One part is a separate question.

The site lists several common misconceptions, and what the correct way of things really are, but doesn't list any references.

Q1. Is what is written on the site correct?

I quoted in the 7 "main misconceptions" from the site, and also brought another one from it that I found interesting. The quotes are shortened down, to not take up too much space. I recommend going to the site and read it.

All electric currents are flows of electrons? Wrong.

Electric currents are not always flows of electrons, they are flows of any type of electric charge. Both protons and electrons possess exactly the same amount of 'electricity.'1

"Electricity" is made of electrons, not protons? Nope.

Charges of "electricity" are carried both by electrons and protons.1

Electrons are a kind of energy particle? Wrong.

Electrons and protons are matter, not energy.1

"Electricity" carries zero mass because electrons have little mass? No.

Quantities of "Electricity" (meaning charge) have weight because charge is part of matter particles.1

Positive charge is really just a loss of electrons? Wrong.

Positive charge is not made of "missing electrons." Positive charge is a genuine type of charge in its own right.1

Positive charge cannot flow? Totally wrong.

Electric currents in a metal wire are flows of electrons, but in many other materials both the positive and negative charges can flow.1

To create "static" charge, we transfer the electrons? Not always.

"Static" or imbalanced charges can be created by removing electrons from a neutral atom.1

THE "ELECTRICITY" INSIDE OF WIRES MOVES AT THE SPEED OF LIGHT? Wrong.

In metals, electric current is a flow of electrons. Many books claim that these electrons flow at the speed of light. This is incorrect. Electrons in an electric current actually flow quite slowly, at speeds on the order of centimeters per minute. 1

First part of the question is just trustworthiness of the page. Second part is about the teaching. Teaching is tricky, and what the page goes against is teaching misconceptions to kids in school, which then stick till when they are older, and they struggle to learn the right things, because they was taught wrong to begin with.

Q2. Is teaching misconceptions a bad idea or is it unavoidable?

Third part of the question is too big to include here, I will provide a link to its own question. The third part is about how spread out the misconcepts are, how commonly they are taught. It's a too big question to have here, so take that part over to that question.

Q3. http://skeptics.stackexchange.com/questions/15855/how-spread-out-are-the-misconceptions-about-electric-theory

Edit the third part of the question is deleted, it was not very interesting afterall.

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You might get other perspectives if you post it here also - electronics.stackexchange.com –  david blaine Apr 11 '13 at 9:09
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So far as I can tell, what the page says is consistent with what I was taught, it is also correct that we are (at least initially) taught a simplified view that leads to many common misconceptions (e.g. it is commonplace to say capacitors store charge when in fact they don't, they store energy). It doesn't mean that what is taught is "completely off" just that what is taught is a useful but simplified view and uses commonplace terms like electricity and charge whose ordinary meanings are ambiguous. Alas I don't know of a good reference for all this. –  RedGrittyBrick Apr 11 '13 at 9:23
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This question needs some serious work to make it answerable. If the question is "Are the explanations given technically correct?", how about we cut it back to 1 or 2 to make it manageable? If the question is "Are students really taught these falsehoods?", how about we restrict it to a smaller region and period of time, or else it is unanswerable. But the real question is "Is it unreasonable to simplify physics to make it intelligible for pre-pubescents?" The effectiveness and morality of Wittgenstein's Ladder is off-topic here. –  Oddthinking Apr 11 '13 at 11:52
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I feel it's kind of like saying "Newtonian physics though in school are wrong, because they don't mention relativistic effects". –  vartec Apr 11 '13 at 11:54
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I don't want to defend science education (in the US, where I know something about it) much as I think it could use much improvement, but ... Teaching this stuff to kids in a way that is (1) useful to them in making judgements about the world, (2) systematic and (3) prepares them for more rigorous treatments later is hard. Demanding that they cover all the cases and never say anything that is not completely correct is just plain silly. You could probably do that with the brightest of the bright but you will simply confuse most of the class. –  dmckee Apr 11 '13 at 14:44

3 Answers 3

up vote 3 down vote accepted

Author here.

Is all that stuff correct? Certainly. It comes right out of physics texts and this list has been discussed by educators (mostly on PHYS-L, in the net's early days.) For many years I was updating it with numerous slight corrections.

If you find that the material conflicts with what you were taught ...then there's a problem.

That list of common misconceptions was collected from numerous sources, including textbooks, pop articles, and many adult experts (electrical engineers on many forums.) It's not only a list of K-6 textbook problems, since the same problems appear in the general public's understanding of Electricity. The article grew out of a central question during my exhibits design work at Museum of Science in Boston: how should we teach "electricity" in our new exhibit? The K-6 texts we inspected were full of basic factual errors as well as misleading oversimplifications, so we couldn't use them as a basis for teaching. Our goal became: explain classic E&M to little kids and grandparents, but done in a way so as not to breed the numerous barriers which halt further learning. (See "Textbooks Flunk Out", 1999 Boston Globe http://virus.lucifer.com/virus.2Q99/1096.html)

And yes, non-electron currents are common: that's how nerves work, that's how electric currents can exist in dirt and in oceans, and exclusively proton currents are common in battery electrolyte (where they're usually called positive hydrogen ions.) It's a widespread misconception that "electric current" means "electron flow" and nothing else. Perhaps if we were only teaching future repair technicians, then it might be acceptable to avoid non-metal conductors while pretending that all currents were electron flows. But kids who are future engineers and scientists need a wider understanding. (Me, I think the general public would love such a wider understanding.)

Yes, it's acceptable to teach "lies to children," as long as those simplifications don't lead to persistent misconceptions and learning-barriers. E.g. atoms are like little solar systems with electrons orbiting the nucleus? No problem. Those simplifications get updated later, so they're far more useful than harmful. Chemistry techs don't angrily resist the QM concepts of orbitals/clouds, and forever after cling tenaciously to the solar-system model over the rest of their careers. But in electronics, such things are common. The serious problems arise when those oversimplified concepts are never questioned, and they become long-lasting learning barriers which persist into adulthood.

Is this all something new? No, the list was from the late 1980s, and the deeper issue of textbook errors is a major decades-long problem and still being battled by hundreds of people, see for example http://www.textbookleague.org/ttlindex.htm. Even Richard Feynman brings it up in "Judging Books By Their Covers." http://www.textbookleague.org/103feyn.htm Note that Feynman found he could make no headway, and had to give up. That should tell us something.

Are the listed misconceptions an unavoidable consequence of simplifying E&M physics for children? Definitely not, and since I wrote my articles, several grade-school textbooks have appeared which completely avoid the mistakes. A few publishers actually listened to the critics and made major changes. That, or the critics themselves authored new books.

By explaining EM physics at the grade-school level while removing all the typical misleading/wrong explanations, these texts demonstrate that the concepts involved aren't overly sophisticated or fit only for college level. They demonstrate that the problems in earlier books were genuine errors easily removed. And obviously they show that an entire community is working on this problem, not just me alone. And so, more references...

  1. MS Steinberg's C.A.S.T.L.E. electricity curriculum. This was the end result of a 1980s project to redesign high-school material to treat the known student electricity misconceptions via direct hands-on experiments using supercapacitors, bulbs, and hand-crank DC generators. http://www.ptec.org/items/detail.cfm?ID=4438

  2. Smithsonian/National Academies 2002 "Electrical Energy and Circuit Design." The authors built an entire middle-school electricity curriculum from scratch, and avoided every single problem on my list, even including the separate 'static electricity' list. http://www.amazon.com/Electrical-~Science-Technology-Concepts-schools~/dp/0892788968

  3. Prentice Hall's 2007 "Science Explorer" series, "Electricity and Magnetism." Again, no misconceptions from my list. This text is by Dr. C Wainwright of the "castle" capacitor project. http://www.amazon.com/Electricity-Magnetism-Ph-D-Camille-Wainwright/dp/0133651150

  4. G. McWhorter's 1987 "Basic Electricity JE-101," Radio Shack. An electrical engineer simplifies E&M physics while avoiding all the "infectious misconceptions." Interesting that he apparently did this independently before the rise of electricity-misconceptions research, and of course long before I was able to post my own work online. http://www.amazon.com/Electricity-JE-101-Science-Junior-Engineering/dp/B00071OWRE

Note that except for Prentice-Hall, the major K-12 education publishers haven't followed suit. To find this 'repaired' curriculum material, a school district has to obtain their products from outside the conventional channels.

What about all the engineering students who acquired a headful of misconceptions in grade school? Darren Ashby is now (2005) selling a "textbook" which carefully goes through point-by-point and repairs all the damage. So, now I won't have to write one myself! "Electrical Engineering 101: Everything You Should Have Learned in School...but Probably Didn't" http://www.amazon.com/Electrical-Engineering-101-Third-School-but/dp/0123860016

And don't miss that 2002 Sefton paper:

Understanding Electricity and Circuits: What the Text Books Don’t Tell You http://science.uniserve.edu.au/school/curric/stage6/phys/stw2002/sefton.pdf

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Yes I am aware of what I was taught was a bit lacking, the article fascinated me and piqued my interest. I read it fairly long time ago, and at that time I thought "Is this really true?". A problem I see is that with the claim "textbooks are wrong", and then you said reason your article is correct is because it's from physics text. It's word against word, and without being really experienced in electronics, it's hard to ground the claim. Also a bit of a problem with my question is that currently, is like 3 questions, I will probably to divide it into several. –  Wertilq Apr 12 '13 at 8:40
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To clarify: I find that college-level textbooks have only few errors/misconceptions. It's the grade-school texts (and articles aimed at the general public) which contain the drek. And, how did I find this thread! Sorcery! (I ego-surf by watching the list of referring pages on my site traffic sitemeter.com/?a=stats&s=s50wbeaty&r=11) I find the best sites that way, plus occasional conversations about mine. I guess I could figure out how to parse the Apache logs for eskimo.com, so I could strip out all the incoming google stuff seen in that list. –  wbeaty Apr 12 '13 at 9:41
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Oh also: to cut through bs, if someone insists that my articles are wrong, just have them point out the details. Perhaps they'll discover something I need to repair. But that happens less and less, and most often they'll only demonstrate that they have the very misconceptions I'm complaining about. –  wbeaty Apr 12 '13 at 9:45
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@wbeaty Welcome to Skeptics, hope you stick around. :) One thing that we really like here is substantiation of claims and answers. I read through your answer, and found it to be a great answer. Just wondering if you could reference some of the key source material from your research. That way it doesn't appear so much as either original research or an opinion answer. Thank you. –  Larian LeQuella Apr 12 '13 at 18:01
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Good point, I'll go add obvious links to my reference page on misconceptions: amasci.com/miscon/electref.html. For the curious, good intro papers online are Sefton 2002: science.uniserve.edu.au/school/curric/stage6/phys/stw2002/…, and Chabay/Sherwood 1999: matterandinteractions.org/Content/Articles/circuit.pdf. If you're more serious, get hold of the 1985 conf. proceedings 'Aspects of Understanding Electricity.' For kids' naive physics concepts (not textbook-taught errors,) AIP/OP compiled this list: amasci.com/miscon/opphys.html –  wbeaty Apr 16 '13 at 3:34

No. We are talking here about 5-13 years old kids. The concepts that the source talks about are very sophisticated. When we are talking about little children, a level of simplification is needed. I studied (now finishing) a double degree in Physics, and Electrical Eng. and what I've seen is that even in undergraduate and graduate courses in the university, courses that are intended to Electrical or Software Engineers often simplify the physics involved ,to a degree that wouldn't be in physics courses, for better understanding of the general more important principal. For example, you don't need to learn quantum physics, only to know that an electron can only be in discrete levels in an atom.

I'll touch on the 8 claims that you provide here.

Some of the claims that the source makes are plain false. For example, the first and the "static charge" statements. Other statements that the source "falsifies" are right inside a solid materials, and others are right inside metal, since semiconductors, plasma, and Ion currents are quite complicated materials, and that children don't often get to see plasma streams or semiconductors, but most of them associate electricity only with electric wires and maybe simple electric instruments, like light bulbs switches and ovens it's safe to assume that when you talk about electricity to children, even if you don't state so explicitly, you are assuming current inside metal conductors.

Lets look over the statements provided here, and see if they are right. My sources is what I was taught during my physics Bsc. For references you can see the book that was the course book when I studies the basics of Electricity and Magnetism, Electricity and Magnetism from Berkley, or you can watch the course filmed at MIT by Professor Walter Lewin. Some of the answer include some complex material from more advanced courses or subjects, at the end I'll give a list of the books which were the course books when I took those subjects.

All electric currents are flows of electrons?

Yes, they are. There is the concept of positive charge flow, where the charge carriers are holes, however, at the micro level, it is still a flow of electrons, on the opposite side that creates a lack of electrons which "moves". However this is NOT intro level physics, but taught at solid state courses or semiconductors courses. Just to clarify, holes are positive charge carriers, however, holes are not a real particle, they are a representation of a lack of electrons.

EDIT: after consulting a physics professor and doing some more research into this, I realize I was wrong here. Here is the fixed version: Protons are ionized hydrogen atoms, Ion conductance is present in Plasma, liquids, and can be present in some solids. But this isn't present in metals and wires, or any "classic" electrical appliance. since we assume that we are talking to a 13 years old kid, we don't talk about plasma, neurotransmitters, or semiconductors, so yes, inside a metal wire all electric current is due to the displacement of electrons.*

"Electricity" is made of electrons, not protons? Nope.

Charges of "electricity" are carried both by electrons and protons

Not sure what "Electricity is made of electrons, not protons?" means, because Electricity is a concept, not a real things, just like saying that gravity is made of mass, and relativity is made of light. If they mean that both protons and electrons can form electric current, then see previous answer.

Electrons are a kind of energy particle? Wrong.

Electrons and protons are matter, not energy.

Electrons and protons are matter and not energy, photons are energy particles. However, when we talk to a 13 years old kid about transferring energy from the power station to their home, then saying that the powerstation is providing energy in the form of a current that moves electrons, it's a completely reasonable simplification.

"Electricity" carries zero mass because electrons have little mass? No.

Quantities of "Electricity" (meaning charge) have weight because charge is part of matter particles

The only thing I have to say is WTF?!, electrons have mass, and so do protons, but charge is a property, it doesn't "carry mass" it's like saying that because things have length and color, then "length carries a color". There are 2 types of particles that have charge: leptons (electron, muon and tau) and quarks, each of those particles has mass and charge, but charge and mass are properties of the particle, not a particle by itself (protons and neutrons are made of quarks). This is particle physics material.

If the meaning is that electrons have no mass, then yes, they don't have mass. Electrons have ~10^3 less mass than a proton, for all practical purposes, an electron doesn't contribute any mass to the mass of the atom. Since, again, we are talking with kids, and we don't calculate the mobility of different materials (Solid state physics), or about movement of individual electrons (Quantum Physics), then the approximation that electrons have no mass is good enough.

Positive charge is really just a loss of electrons? Wrong.

Positive charge is not made of "missing electrons." Positive charge is a genuine type of charge in its own right.

True, a proton has a positive charge by itself. However since most subjects in nature come with a neutral charge, then in order to have a positive one you will need to take a way a negative charge (electron) and get an Ionized atom with a positive charge. Since kids are taught what is in nature, and nature doesn't have free positive charge without taking away an electron, again, acceptable.

Positive charge cannot flow? Totally wrong.

Electric currents in a metal wire are flows of electrons, but in many other materials both the positive and negative charges can flow

Positive charged particles, i.e. protons can't flow inside a solid matter, only electrons can, in some instances, we will say that there are "holes" that hold a positive charge and they are flowing inside a material, but holes are but a real particle, only a representation for a lack of electrons, protons don't move from their place inside a solid (they can vibrate in place). See first point.

To create "static" charge, we transfer the electrons? Not always.

"Static" or imbalanced charges can be created by removing electrons from a neutral atom.

On the first sentence they say "To create "static" charge, we transfer the electrons" but then they say "created by removing electrons from a neutral atom", which is the same as transferring an electron. You will get static charge if you just "remove" the electron, but the electron has to go somewhere.

THE "ELECTRICITY" INSIDE OF WIRES MOVES AT THE SPEED OF LIGHT? Wrong.

In metals, electric current is a flow of electrons. Many books claim that these electrons flow at the speed of light. This is incorrect. Electrons in an electric current actually flow quite slowly, at speeds on the order of centimeters per minute.

Electricity doesn't move at the speed of light, only light (photons) moves at the speed of light, and the speed of light changes in different materials. This is the only point where I agree with the source. While electrons move at very high speeds, the "current" is their drift speed, which is much slower (I don't know if they are right as to the speed is several cm per sec, but it changes with the magnitude of the applied field, so obviously, the current speed will change, whether you apply 1.5V of 1e5V on the conductor). If there is a text book saying that electrons move at speeds close to the speed of light without saying that the current doesn't flow at that speed, than that textbook is wrong.

Explanation on drift speed vs. speed:

Electrons move in random directions in very high speeds. When we talk about the current speed, we are talking about drift speed. The electron moves in different random directions inside the material, then collides with another particle, loses all it's speed and starts moving in a new random direction. When an electric field is applied, then the electron will move slightly more to a single direction, and thus drift in that direction. This is also why the current speed and not acceleration is relative to the force applied. A good video explaining this subject

Final conclusion:

What we have here is a post (and I would even go so far as call it a rant) that kids smaller than 14 aren't taught university undergraduate and graduate level physics, with all the fine nuances. While in some cases the source may have merit and a viable point if it was addressing that non-physics students (like EE, CS, MEC and others) are taught over simplified physics, the source doesn't address them, but, instead addresses small children in elementary school. Even if to claim that this is addressed to grown people who don't work at physics related jobs, or have physics related occupations would be, it would still be way too petty, as people who don't need the exact details, could be left very well with a basic understanding of the subject.

You can't explain physics at the level that the source demands without a lot of time being spent at explaining and learning all the subjects that are needed for a full and real understanding, including high level math, basic (university basic = high-school advanced) chemistry, and the physics that is at the core of those laws, including, particle physics, relativity theory, quantum mechanics, statistical physics, thermodynamics, EM theory and maybe even more, go to any college or university web site, look at the list of courses needed to be taken by students before they take the solid state physics course, this all you need to know to understand, why certain particles can conduct in certain material and other in other materials.

Because a full explanation is a very very very long and hard explanation, it's better to leave people and especially kids with some basic knowledge of the principals behind the phenomenons that they see every day, than to leave then with no explanation at all.

You can see from the source material at the undergraduate level that I provide here, that all those nuances and fine details are taught to students that learn the subject at the university, and that there isn't a fear of a physicist who thinks that protons don't have a charge associated with them.

Sources for other subjects touched on here:

Particle physics: No course book, but you can see a full Stanford course on this subject on You Tube

Semiconductors and Solid State Physics: Solid State Physics /Ashcroft & Mermin

*- Electromagnetic theory also knows to deal with magnetic currents, i.e. the displacement of magnetic charge. But since magnetic charge carriers were never found in nature, this is a purely theoretical aspect of the EM theory.

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I just took part of the claims to not make the question too long, if you have any misunderstandings, read the homepage all the questions comes from, they explain details further. –  Wertilq Apr 11 '13 at 11:07
    
Also I was taught that electrons almost moves at the speed of light and that it is as fast as the speed of light depending on material, and with that that electricity moves (almost) at the speed of light. –  Wertilq Apr 11 '13 at 11:11
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At the risk of making this close to unanswerable, your first paragraph (and sentences sprinkled throughout) are anecdotes and are not acceptable. Just because you were taught correctly, doesn't mean all/most people were. Just because you were taught the correct thing in your BSc doesn't mean 5-11 year olds are, as in the original claim. –  Oddthinking Apr 11 '13 at 11:44
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Almost all your objections are differences in style, except the "current is carried by electrons" is right in the source and your counter is wrong. Appropriate solids can conduct protons also (e.g. ice), and you completely neglected liquids. This is kind of important since the majority of current in your nervous system is moving sodium and potassium ions. (I'm not sure if there are any practical instances of positive static electricity.) So this doesn't make for a good answer. –  Rex Kerr Apr 11 '13 at 14:48
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"so when there is a flow of protons, it's not electric current" Yes it is. –  endolith Apr 11 '13 at 21:06

Is the theory commonly taught in school, as untrue as the page claims?

This may be slightly fuzzy because it has been many years. However, when I was in school (high school and some electrical engineering) we learned that:

  • electrical charge was transfer (build-up) of electrons.
  • Protons are part of the atoms and when there are a lack of electrons you have a positive charge.
  • Electric current is the flow of electrons and measured in Amperes (Coulombs/second).
  • Electricity can flow through non-metals in different ways like Ions in water

He almost seems to be saying most of this is wrong. But then goes on to explain that it is not wrong, but there is more to it.

For example, from the website:

ELECTRICITY IS MADE OF ELECTRONS? Wrong. Other things flow besides electrons. It's true that electric current in metals is a flow of electrons.

The key word in this is *in metals.* So really, what we are taught in school wasn't incorrect but applies to the electricity we typically use and study, which is circuits consisting of metallic conductors.

Even the Wikipedia article on Amperes (measure of electric current) states the units in electrons per second:

In practical terms, the ampere is a measure of the amount of electric charge passing a point in an electric circuit per unit time with 6.241 × 10^18 electrons, or one coulomb per second constituting one ampere.

What we are taught is not incorrect, I think it is just incomplete i.e. oversimplified as you said. You can go into more specialised studies and expand upon the things you learned previously.

So to answer your question, from the little I have been reading through the site it seems the site is correct. Just misleading at first, telling everyone they are "wrong", when really what they were taught is just "oversimplified".

There is nothing ground-breaking in this site and he almost seems like someone ranting against the education system for not teaching elementary grade children advanced topics of study (high school and university).

My wife teaches grade K/1. Everything is very oversimplified. Teaching them how to measure is basically "Is this bigger than this?" No units or anything... Every step you learn is probably easy to think "this is all there is to it" until you get to the next level... it's human nature to be curious about everything, but also I find human nature to think you know everything about a subject once you learn a little about it. It's not until you really get into it that you find out you know nothing.

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You didn't really answer whole the question. I appreciate someone else coming with their experience from school and what was taught, it is half the question. So at university you was taught what the home page went against? If so, do you know which of them is true, what was taught in your school, or the claims of the home page? –  Wertilq Apr 11 '13 at 8:54
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well the home page says things like "Other things flow besides electrons. It's true that electric current in metals is a flow of electrons. " So really, what I was taught wasn't incorrect but applies to the electricity we typically use and study, which is circuits consisting of metallic conductors. –  fungku Apr 11 '13 at 8:55
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Yea the claims on the homepage is more or less, "current study is oversimplified". For many purposes the details doesn't matter, but I am curious if the page is correct or not. Also you missed a number when you typed in when you graduated. –  Wertilq Apr 11 '13 at 8:58
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From what I am reading it seems the site is correct. Just misleading at first, telling everyone they are "wrong", when really just "oversimplified". In chemistry I vaguely remember electricity needing transfer of ions if transferring through water for example. So that is another case where it is not "a flow of electrons". –  fungku Apr 11 '13 at 9:04
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My wife teaches grade K/1. Everything is very oversimplified. Teaching them how to measure is basically "Is this bigger than this?" No units or anything... Every step you learn is probably easy to think "this is all there is to it" until you get to the next level... it's human nature to be curious about everything, but also I find human nature to think you know everything about a subject once you learn a little about it. It's not until you really get into it that you find out you know nothing. –  fungku Apr 11 '13 at 9:36

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