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View Full Version : I've forgotten how to do long division


Lazarus and the Gimp
28-06-2006, 18:38:50
And I'm not entirely sure I can remember how to do multiplication either. I stake my claim as the forum's biggest maths dunce.

Christoph
28-06-2006, 18:40:10
1+1=2 jepjepjep

Venom
28-06-2006, 20:06:38
Who needs division? It's just so divisive. We need to be about bringing numbers together.

JM^3
28-06-2006, 20:09:38
you can just use a calculator

I can still do multiplication and division (of course, I don't remember learning how, I saw them and knew how), however, I can no longer quickly do more complicated operations in my head quickly (I use to be able to look at two 3 digit numbers and multiply them instantaneously).

Jon Miller
(well, 3 digit numbers isn't too complicated, but it is more then what I can do now (1 digit numbers are instanteous, more digits and it takes longer and longer ammounts fo time))

Lazarus and the Gimp
28-06-2006, 21:40:35
Reach my age, dear Jon, and you won't even be able to remember your own wife's name instantaneously.

HelloKitty
28-06-2006, 21:45:30
Jon is getting married?

JM^3
28-06-2006, 21:47:05
no time soon

I have a hard time remembering my freind's names from a few years back (undergrad)... people who I don't know very well who I have met recently can forget about me knowing their name..

JM
edit: basically this is the worst year on the romantic front since my junior year of college (my senior year of college was the first time I even approached having a GF)

(I still didn't of course.. but I did ask a girl out, and went to movies/out to eat/a few other things with another girl)

alsieboo
28-06-2006, 22:02:29
I was sick the day they did long division. And long multiplication. The short ones too.

Provost Harrison
28-06-2006, 22:13:55
You know Laz, I was thinking about this the other day, and I don't think I can remember how to do long division either :lol:

Gary
28-06-2006, 22:21:35
Get on with you all. 'tis easy :D

paiktis22
28-06-2006, 22:22:04
Noone can. It's the success of the educational system.

paiktis22
28-06-2006, 22:22:54
X-Post. Gary can do it. Of course since he's writing in times new roman. :D

Oerdin
28-06-2006, 22:24:36
Off to the math gulog with you!

Greg W
29-06-2006, 03:06:35
Long Devision? Pfft, it's not THAT hard. Mind you, I couldn't do what Jippon Manilla does with multiplying 3 didgit numbers in his head.

Gary
29-06-2006, 05:59:32
123 x 100 = .... um ... er ... 12300 !!! :D

Greg W
29-06-2006, 07:31:27
Idiot. :p

Funko
29-06-2006, 08:06:08
It really isn't hard.

http://www.mathsisfun.com/long_division2.html

Nills Lagerbaak
29-06-2006, 08:18:18
Originally posted by alsieboo
I was sick the day they did long division. And long multiplication. The short ones too.


Long multiplication?! Does such a beast even exist?

MoSe
29-06-2006, 08:20:29
hhhmmm....

I think we just call that division...
Long? What's a "short" one then?

I think I can easily multiply 5 digit numbers in my head...
Just gimme 4-5 minutes to do it :cute: :D

If you wanna talk about math prowess, I had in highschool a mate who could do 10 digit numbers SQUARE ROOTS.
He DID look a bit like Rainman indeed.

Tizzy
29-06-2006, 08:27:25
I've forgotten too.

I always hated long division though. I moved school when I was 10 and the school I left hadn't started teaching us long division yet and in the new one everyone learnt it months ago. And I had the least patient teacher in the world trying to teach me. I think she made me cry.

Nills Lagerbaak
29-06-2006, 08:40:32
Long division is distinctly different to short division. Long mulitiplication is a simple extension of short multiplication.

Don't ask me how to do long division though :)

King_Ghidra
29-06-2006, 08:45:34
how do you do long division?

Funko
29-06-2006, 08:50:35
Long division is just doing a lot of 'short' divisions until you get the correct answer.

So I'd dispute that there is difference. 'Short' division is exactly the same, but the case is so simple that you only need to do one step rather than several.

Venom
29-06-2006, 11:43:54
Shut up, dork.

Gary
29-06-2006, 11:44:40
As I understood it short division related to the tables one should have memorised (1 to 12) at primary school, so there was no reason to go noting down "working" under the "sum".

Long division had a larger divisor (13 and upwards) and so you had to do the division gradually using digits from the left onwards. In effect one made a guess at how often the divisor went into the first few digits and hopefully you were correct. Multiplied the guess by the divisor and subtracted it from the digits considered so far. to work out what the remainer was, and then brought down the next digit to start the procerss all over again.

Basically short division is mental arithmatic, long division isn't. It needs working out shown on the paper.

MoSe
29-06-2006, 12:59:51
I'd say the algorithm to work out square roots on paper was a bit more challenging, I probably wouldn't be able to remember it

although the process should have been similar to the one of long division, taking digits 2 by 2

Japher
29-06-2006, 13:13:29
I can't get past Brits calling it Maths

The perplexity of the grammar prevents me from actually bothering with the subject all together.

Funko
29-06-2006, 13:36:49
maths because it's short for "mathematics"

Venom
29-06-2006, 13:37:55
If you're shortening the name, why not just shorten it to math. Your version would be mathsematics.

Funko
29-06-2006, 13:42:14
We're treating it like an abbreviation of a pural, mathematics might not technically be a plural, and the US way might even be the expected grammar but the whole point of English is having bizarre spellings and grammatical exceptions to confuse non-native speakers.

Venom
29-06-2006, 13:46:17
Yes. English is awesome for that.

Japher
29-06-2006, 14:30:26
and its a good excuse to not bother

Lurker the Second
29-06-2006, 14:55:33
You need an excuse not to bother now?

Japher
29-06-2006, 15:00:26
I guess so

Lurker the Second
29-06-2006, 15:07:52
Then you're a loser loser.

Japher
29-06-2006, 15:10:34
I learned it by watching you!

Tizzy
29-06-2006, 15:12:58
Originally posted by Lurker the Second
You need an excuse not to bother now?

people complain otherwise

Gary
29-06-2006, 15:13:42
Have you even taken stat ?

I never got on with it. Black art.

MoSe
29-06-2006, 15:33:54
I thought I loved it.
Then I took it at the uni.
It's mostly illogic and pointless. Got one of my worst marks (23/30 IIRC).

So I console myself in practicing as a charlatan here.

Nills Lagerbaak
29-06-2006, 15:35:14
Hm, you can make good money modelling financial markets with stats.

King_Ghidra
29-06-2006, 15:36:43
I don't know Statistics mathematically, but i know it from business use and they are truly a black art. In fact on recent course i did that covered in part statistical deception, i was immediately confronted by a technique my boss had used to secure this year's bonus for us all

scarily i now know about terrible terrible things like ANOVA and chi-squared, plus i do a mean polynomial trendline

MoSe
29-06-2006, 15:40:01
that's mean!
It took me years to forget such things


and then, in my work, I had to be confronted with account managers stating *in print* that 104% of their HelpDesk Tickets had been closed in time

PS:
i do a mean polynomial trendline
of course I let Excel do that for me ;)

King_Ghidra
29-06-2006, 15:43:19
fuck i don't plot it by hand!

without excel i'm powerless

Nills Lagerbaak
29-06-2006, 15:53:36
Amatures! There are three levels in software. 1st do it by hand. That qualifies you to do it in Excel, which in turn qualifies you to use a fancy programme!

Nills Lagerbaak
29-06-2006, 15:54:41
Originally posted by MoSe
that's mean!



No, it's just and average response

Koshko
29-06-2006, 21:06:33
Did you know that at one time schools actually thought children how to do math WITHOUT the aid of a calculator?

THE MORE YOU KNOW

Dyl Ulenspiegel
29-06-2006, 21:19:43
Originally posted by MoSe
hhhmmm....

I think we just call that division...


Us too, we just write it down a bit differently from the example someone (I assume Funko) linked. Oddly enough, I still can do it, and even use it sometimes.

Dyl Ulenspiegel
29-06-2006, 21:20:19
Originally posted by Koshko
Did you know that at one time schools actually thought children how to do math WITHOUT the aid of a calculator?


Oh yes, just look what that has done to me... :cry:

Provost Harrison
29-06-2006, 22:22:22
They could get the world's best scientists to do the hoovering in their office, but that would be a waste, would it not?

Gary
30-06-2006, 07:44:19
Only just checked Funko's example. Hmmm ... any dividing by 25 is a candidate for short division :)

MoSe
30-06-2006, 07:51:56
Division: ~15k soldiers
Short Division: 10k soldiers?
Long Division: 20k soldiers?

Gary
30-06-2006, 07:58:34
That's "fat" and "thin" divisions :)

Funko
30-06-2006, 08:07:18
Originally posted by Gary
Only just checked Funko's example. Hmmm ... any dividing by 25 is a candidate for short division :)

83736273662729108276/25

Funko
30-06-2006, 08:08:26
Debatable whether something like that is easier to do as a long division by 25 or a long multiplication by 4.

Dyl Ulenspiegel
30-06-2006, 08:14:41
Originally posted by MoSe
Division: ~15k soldiers
Short Division: 10k soldiers?
Long Division: 20k soldiers?

Short Division: 15k italian soldiers
Long Division: 15k dutch soldiers

MoSe
30-06-2006, 08:20:58
Mr.lonG

Dyl Ulenspiegel
30-06-2006, 09:50:10
Shortest Division: 15k dutch architects

Gary
30-06-2006, 10:57:17
:D

83736273662729108276/25 May look difficult but in reality it's just long, tedious and boring. (And because of that subject to a high risk of error.) One would, of course, have to have the dividend written down to refer to.

In my head ...

25s into 83 obviously 3 r 8 write down or enunciate the 3 as the answer, then forget it.
25s into 87 obviously 3 r 12 write down or enunciate the 3 as the answer, then forget it.
25s into 123 obviously 4 r 23 write down or enunciate the 4 as the answer, then forget it.
25s into 236 obviously 9 r 11 write down or enunciate the 9 as the answer, then forget it.
25s into 112 obviously 4 r 12 write down or enunciate the 4 as the answer, then forget it.
25s into 127 obviously 5 r 2 write down or enunciate the 5 as the answer, then forget it.
25s into 23 obviously 0 r 23 write down or enunciate the 0 as the answer, then forget it.
25s into 236 obviously 9 r 11 write down or enunciate the 9 as the answer, then forget it.
25s into 116 obviously 4 r 16 write down or enunciate the 4 as the answer, then forget it.
25s into 162 obviously 6 r 12 write down or enunciate the 6 as the answer, then forget it.
25s into 127 obviously 5 r 2 write down or enunciate the 5 as the answer, then forget it.
25s into 22 obviously 0 r 22 write down or enunciate the 0 as the answer, then forget it.
25s into 229 obviously 9 r 4 write down or enunciate the 9 as the answer, then forget it.
25s into 41 obviously 1 r 16 write down or enunciate the 1 as the answer, then forget it.
25s into 160 obviously 6 r 10 write down or enunciate the 6 as the answer, then forget it.
25s into 108 obviously 4 r 8 write down or enunciate the 4 as the answer, then forget it.
25s into 82 obviously 3 r 7 write down or enunciate the 3 as the answer, then forget it.
25s into 77 obviously 3 r 2 write down or enunciate the 3 as the answer, then forget it.
25s into 26 obviously 1 r 1 write down or enunciate the 1 as the answer, then forget it.
Then either announce a remainer or one, or note that the answer has a fractional part of a twentyfifth

You don't have to have the whole nunmber in your head at the same time, just so long as you can hold the relevant bits.

Or as you mentioned, you could just multiply by 4 and move and the decimal point in your head ;) :p

Funko
30-06-2006, 10:58:24
Gary, that is Long Division.

Gary
30-06-2006, 11:06:47
The important difference isn't whether you take a bit at a time but whether you need to note it down. That is mental arithmetic so was it qualifies as short division.


Example how do you tackle 12687/9 in short division. By working your way across in your head.

Funko
30-06-2006, 11:56:50
I dispute that the difference is whether you write it down or not, the method is the long division method.

Also, looking at your working, you are wrong. You go wrong on the 236 line. So it seems you can't do it mentally after all.

MoSe
30-06-2006, 12:05:58
Originally posted by Funko
I dispute that the difference is whether you write it down or not, the method is the long division method.

So it's only a short division when you know it by heart?

Gary
30-06-2006, 12:19:03
If you reject that as the difference then you would probably not see the any difference between short and long.

Funko
30-06-2006, 12:52:57
Short is what you said, division where you just know the answer, if you need to use that method, it's long division. Whether you write it down or not is irrelevant.

Chris
30-06-2006, 12:56:24
Calculation is for lesser men.

Venom
30-06-2006, 12:59:57
Short division is when Mr G gets cut in half.

Chris
30-06-2006, 13:01:49
Bada bing.

Lazarus and the Gimp
30-06-2006, 14:48:42
Originally posted by Gary
The important difference isn't whether you take a bit at a time but whether you need to note it down. That is mental arithmetic so was it qualifies as short division.



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