# Poor math skills are OK?

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Elsewhere on this group someone asked about a scale conversion calculator, and it's not the first time it's been requested either. I've always thought this an odd thing, admitting that you aren't able to perform calculations requiring fractions and proportions, something that is taught in the fourth, fifth, or sixth grade in the US.

I guess that's a(nother) problem with our society - we are so willing as adults to just laugh it off when others say: "Oh, I can't do that math stuff. I was never any good at it so I just gave up. Nobody uses it anyway." It's in our culture that this is the norm. It's OK that you can't do these sorts of calculations. "Word Problems" - a national joke. Math is for nerds. No stigma, no concerns, no social negatives.

The reaction ought to be the same as if somebody had said: "Oh, I can't read. I was never any good at it so I just gave up. Nobody uses it anyway." Both skills are equally important in adult life.

Oh well.

BTW, let me cut you off before you guys go off on one of pet tangents, the US educational system. This really has nothing to do with teachers or schools. Please, save your electrons for some other thread.

KL

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• posted

Well I admit to sucking at word problems, mainly because in school it was always "Johhny and his apples" or "Eddie and his lawn mower".....wrong way to teach word problems IMHO, use problems based on something a kid might give the vaguest damn about or can at least visualize. As for math skills, I'm rusty, very rusty but I can do it. I don't bother with scale conversion for copiers though, not close enough or distortion free enough for my usage. I get plans scanned as a 1:1 .tif file and rescale after redrawing in a vector program.

As an example, I take a set of 1/16":1' battleship plans and scan them

1:1 .tif so the drawing in the raster image is literally 1/16":1', then draw an X and two Y axes at appropriate points. Clean up any scanning artifacts/noise, delete anything I don't need (like the exact internal layouts of decks) then use Wintopo to roughly vectorize them (the free version is a very rough vector, the paid version is much nicer). Import to a CAD package and lock the layer using a bright color to refer to. Then draw a 1:1 set of axes and use rescale/referent command to make the drawing truly 1:1. Then redraw all lines as needed using various colors and layers as makes sense to me. Finally delete the original reference layer and again rescale to whatever my target scale is. Why the extra step of rescaling to 1:1, easy, I can make a library of drawings for common elements like guns, directors, radars, paravanes, torpedoes, etc. and drop them in where needed on any ship that uses that element. It also lets me run checks off of the lift & loft tables and half lines tables using the real measurements. Thus I get an almost perfectly rescaled drawing that's clean and with only the lines I need to make a model. Then I have to get it pen plotted but no big deal. Takes a little more skill and a hell of a lot more time than rescaling on a copier but I haven't seen many copiers that can handle paper 36-42" wide and 6-24' long (the "copiers" that can handle it aren't even copiers, they're large format scanners that drive large format laser printers and most cannot do fractional percentages).
• posted

Although I'm old enough to have learnt fractions at school (in the UK), nowadays most (that's an assumption on my part) of the civilised world uses the metric system, therefore the average thirty year old in Europe probably hasn't ever been exposed to fractions till they encounter an old drawing or dimensions table.

Oddly, I notice (I presume because of NATO) that the US military seem to refer to metres and kilometres.

JH

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As far as numerals go, is this also the reason dumbasses all over eBay don't know how to use Roman numerals? Like I always see listings for a "Mirage 111" (huh, maybe "Mirage III") or a "SPAD X111" (SPAD XIII) or what gets me more than "WW2" (WWII), (which may be acceptable now, I don't know. 25+ years ago my teachers marked "WW2" wrong), is WW11! WORLD WAR ELEVEN!!!!!! Gimme a f'ing break.

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I've always admired anyone who can do complex math problems in thier head. Consider it a gift.

When I was in High School, (early eighties) therer were no computers and typing was still considered a "girls" curriculum. Most of the guys were taking metal shop. I opted for taking three years of typing, because frankly, thats where the girls were :-) I can now type over 50 wpm, and still have yet needed help to repair a lawnmower.

I agree that its not a problem with either schools or teachers. Everyone has a weakness. Mine is math.

• posted

"dereman" wrote

I also never did all that well in math. I have a Masters degree in engineering, and I can't do complex math in my head. I can't even scale off drawings myself without taking a pencil to paper and ciphering 36/1.23 = X/2.70 before I solve for X. However, I at least have the patience and willingness (there ain't much knowledge involved) to sit down for (literally) a few seconds and figure it out. I'd be ashamed if I couldn't.

My sister once asked me: "I made \$52 worth phone calls last month and \$36 of them were sales calls. My phone taxes were \$13. How do you figure out what part of the taxes can charged with the sales calls?" I wrote a little cipher on a page of her phone bill and she was grateful. Eleven years later I was visiting her house and saw that phone bill page tacked up above her desk. Even if she still wasn't able to figure it out for herself, she at least realized it and knew enough to keep the instructions handy. That's more than I can say for many people.

KL

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That depends on what school you went to. In my (girls') school, if you had good grades you were in the "academic" curriculum (algebra, chemistry, physics etc.) and if you had lower grades you were in "commercial" (typing, bookkeeping etc.). No one gave any thought to those "academic" students needing to type *term papers*, much less use computers...

Sister Mary

M. J. Rudy snipped-for-privacy@hotmail.com

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Kurt I wholeheartedly agree with your statement. I learned fractions in grade school and was a straight A student all through school. I even worked at the Chicago Options Exchange, doing nothing but fractions. I had to pass a very rigorous math test to even be hired. Fast Forward 20 years and for some reason I cannot do fractions to save my life. I seem to have had my memory erased when it comes to that kind of math. I guess when you are young and they are prepping you for "real life" it is never a consideration that if you don't need the math skills you may forget them. Cheers, Max Bryant

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Yup, highly infuriating. Even our good friends at Revellogram are guilty. Their latest release of Revell's Spitfire II has "Spitfire 11" on the box. You'd think someone would've known better. Cheers,

The Keeper (of too much crap!)

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Good keeping there!

The Keeper (of too much crap!)

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Kurt,

Evidently this math problem is not just in the U.S. Recent comparisons of math tests in Europe show that even there there's a problem with falling scores.

As for me, I've got a kid in second grade and his public school here in Maryland started him on the concept of fractions in the first grade.

John Hairell ( snipped-for-privacy@yahoo.com)

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• posted

Not only in the US Kurt....

• posted

It really depends on if you go on to need to use those skills after you've been taught them in schools. The method of teaching might have some bearing on this too. I did learn how to calculate with fractions but in the 12 years since I've never had to do it apart from in exams. I can vaguely recall how to do it but would need to read up on it to be certain.

Nick

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Another thing regarding numerals bugs me 'cause it's stupid. Why can't people keep years & feet straight? I bet there are more 57'(feet) Chevrolets on eBay than there are '57 models! And this year is the "Class of 04' "! What gives with that mess?

• posted

I suspect that calculation using fractions is becoming a lost art because we rely so heavily on calculators, which typically yield decimal results. How many people can look at .375 (or 37.5%) and know instantly that it is 3/8? Our actual need to use fractions is probably much reduced; the stock market relies on decimal values now, and the increasing use of the metric system limits the fractionating generated by the English system (unless you're a cook).

The problem with the visualization of word problems is more disturbing, although I see in my daughter's Algebra II book that the teaching methods address this very directly and (IMO) effectively.

Certainly, part of this is repetitively doing these sorts of calculations. I can't remember any trigonometry, but I'm still quite good with most of the algebraic and geometric math elements, since I've had cause to use these over the years (programming, spreadsheeting, tutoring kids).

Scaling is not really a problem if you simply want to convert from one '1/x' scale to another, unless you have trouble visualizing the scale shift. The greater problem is converting numbers into actual measurements, especially with the English system. Something that is

4'10" in real life and scaled to 1/48, and which you neeed converted to 1/72, is effectively reduced in size by 1/3. This gives you (1/48) * 4'10" for the original, or 1/12' + 5/24". Now, divide by 3 and multiply by 2 to convert to 1/72: 1/18' + 5/36". The answer is 29/36"--good luck finding that on a ruler. The decimal equivalent, .8056", is probably close enough for modeling purposes to 8/10 of an inch. If you insist on using a standard ruler with binary divisions (1/2, 1/4, 1/8), your closest approximations will be 13/16" or 55/64". I can do this kind of math, but would prefer not to, which is why I have a Murphy's Rule with 1/48 and 1/72 scale on them. Of course, if you're fortunate enough to be working with metrics, the problems are much easier.

Mark Schynert

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This is a subject I am going to stay off of for the sake of my Blood pressure. A couple of the trainee draftsmen I had over the years were the source of much gray hair. As a draftsmen you should be able to add, subtract, multiply and divide, right?

Bill Shuey who is very happy to be retired!

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It's about time they figured that visualizing word problems was a problem....and addressed it.

Now you know why I do the CAD conversion and work 1:1 in CAD, I can use actual measurements then scale down when I'm done.

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I guess it starts because people know there's an apostrophe in there somewhere so they stick it at the end for completeness. I'm a 'picker' about things like that. Sister Mary Ruthless sent me a humourous piece on misspelling words as long as the first and last letter were right. I had trouble reading it because I 'have' to have everything in its proper place. I'm also too 20th century in that when I see something listed as '04 I think 1904. Since 2000 I've been using the full number when dating something. Occasionally I get a form where it's a bit crowded but I still use the full year number if I can. This also applies to other centuries. Only the 20th can be abbreviated and make sense to me. For real fun you should hear my mother try to pronounce '2004'. ;)

Bill Banaszak, MFE

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One of my favorites was a Sci-Fi website that had a piece of fan fiction that had a UFO being chased by an F-III.

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