[Poll] Do you remember how to do long division and multiplication?

[jagec]

Originally posted by: RossGr

Originally posted by: jagec

Originally posted by: RossGr
Once you start adding zeros in the long division problem there are only 23 possible remainders (0 - 22) so it is not possible to go more then 23 digits without repeating or terminating.

I don't think I understand what you're saying. Are you implying that doing long division by hand has a built-in maximum of 23 sig figs? How come? Or are you talking about calculators?

I am speaking about the the given problem, 8945/23. In ANY long division problem the denominator determines the max number of digits posssible before the quotent terminates or repeats. This is an application of what is known as the Pigeonhole property.
edit:
Actually Pigeonhole Principle on wiki.

I see...interesting. Hmm, what if you divide by an irrational number? Does this only hold true for integers, or for rational number, or for all numbers?

 

[RossGr]

Originally posted by: jagec

Originally posted by: RossGr

Originally posted by: jagec

Originally posted by: RossGr
Once you start adding zeros in the long division problem there are only 23 possible remainders (0 - 22) so it is not possible to go more then 23 digits without repeating or terminating.

I don't think I understand what you're saying. Are you implying that doing long division by hand has a built-in maximum of 23 sig figs? How come? Or are you talking about calculators?

I am speaking about the the given problem, 8945/23. In ANY long division problem the denominator determines the max number of digits posssible before the quotent terminates or repeats. This is an application of what is known as the Pigeonhole property.
edit:
Actually Pigeonhole Principle on wiki.

I see...interesting. Hmm, what if you divide by an irrational number? Does this only hold true for integers, or for rational number, or for all numbers?

This is on the integers. But, to actually do long division on a irrational number you have to truncate it, effectly tranforming to a problem on the integers.

 

[divinemartyr]

I am 29 and can do both without any problems. I haven't done either in years, but I guess it's just never left my brain.

 

[SsupernovaE]

I can do both quite easily in my head. Being unable to write with my hands has required me to adapt.

 

[WHAMPOM]

I am kinda fuzzy on multiplying and dividing fractions. Just don't remember which to invert and multiply anymore. 1/2X1/4=1/8 I know but division?

 

[0roo0roo]

i remember trying it a while back because i suddenly got the thought that i wasn't sure i knew anymore
i botched the first two attempts before i figured it out.
not quite like riding a bike

 

[Flash1969]

Originally posted by: jman19

Originally posted by: djheater

Originally posted by: sdifox
who can't do that???

I'll be the first to admit that I couldn't.

I'm 32, only took up to geometry in high school.
I've never needed to know how to do long division or large number multiplication in my head and be exact. I've always been able to consult a tool or resource to find the answers I needed.

Our culture tends to feel that math fluency is a primary indicator of intelligence and potential success, because of this arts, language, and social sciences are often underfunded, which is unfortunate.

High school?

Don't you learn long division in elementary school?

This is pathetic...

Who gives a shit? It is rarely needed in everyday life. Useless "knowledge" FTL.

 

[ForumMaster]

17 here. can do both without a problem.

 

[Tiamat]

yup, use it almost all the time. Comes into handy for solving series of differential equations etc.

 

[Epic Fail]

Originally posted by: RossGr
Once you start adding zeros in the long division problem there are only 23 possible remainders (0 - 22) so it is not possible to go more then 23 digits without repeating or terminating.

the correct answer is 388.91304347826086960869...

starting after 15 digits, the last 5 digits repeat. Most calculators will not show 15 digits good ones calculate more then they show. Few, if any will give the correct answer to a problem like this one.

The repeating has to be for all the digits, it can't start that late.

388.(9130434782608695652173)(9130434782608695652173)(9130434782608695652173)....

 

[RossGr]

Originally posted by: yamadakun

Originally posted by: RossGr
Once you start adding zeros in the long division problem there are only 23 possible remainders (0 - 22) so it is not possible to go more then 23 digits without repeating or terminating.

the correct answer is 388.91304347826086960869...

starting after 15 digits, the last 5 digits repeat. Most calculators will not show 15 digits good ones calculate more then they show. Few, if any will give the correct answer to a problem like this one.

The repeating has to be for all the digits, it can't start that late.

388.(9130434782608695652173)(9130434782608695652173)(9130434782608695652173)....

Really???

Did you actually DO the problem? Just why can't it start that "late".

Justify your response please.
BTW, I did the division by hand, the number I gave is correct, yours is not.

 

[jagec]

Originally posted by: yamadakun
The repeating has to be for all the digits, it can't start that late.

388.(9130434782608695652173)(9130434782608695652173)(9130434782608695652173)....

There's nothing magical about a decimal place.

Even if your answer is correct, we could move the decimal place on the numerator over by one and get

38.8(9130434782608695652173)(9130434782608695652173)(9130434782608695652173)....
or 3.88(9130434782608695652173)(9130434782608695652173)(9130434782608695652173)....

or 388(913043.4782608695652173)(9130434782608695652173)(9130434782608695652173)....

Therefore making it "start" repeating later or earlier.

 

[jman19]

Originally posted by: Flash1969

Originally posted by: jman19

Originally posted by: djheater

Originally posted by: sdifox
who can't do that???

I'll be the first to admit that I couldn't.

I'm 32, only took up to geometry in high school.
I've never needed to know how to do long division or large number multiplication in my head and be exact. I've always been able to consult a tool or resource to find the answers I needed.

Our culture tends to feel that math fluency is a primary indicator of intelligence and potential success, because of this arts, language, and social sciences are often underfunded, which is unfortunate.

High school?

Don't you learn long division in elementary school?

This is pathetic...

Who gives a shit? It is rarely needed in everyday life. Useless "knowledge" FTL.

Yeah, division is really useless...

 

[jjones]

Originally posted by: jman19
Anyone who can't do either of long division or multiplication is a disgrace... how the hell did you get past elementary school??

 

[911paramedic]

I hope this is a parody thread, for humanities sake.

 

[paulxcook]

I'm 23, able to do both, though I got bored with the long division after about the 8th decimal place. I checked with a calculator and I had it right up to that point, so I stopped.

 

[Flash1969]

Originally posted by: jman19
Yeah, division is really useless...

Yes, being able to do it by hand is. Useless to a majority of people.

 

[DnetMHZ]

I'm 30+ and can still do it in my head.

 

[jman19]

Originally posted by: Flash1969

Originally posted by: jman19
Yeah, division is really useless...

Yes, being able to do it by hand is. Useless to a majority of people.

What if you don't have a calculator or computer near you? This is some really basic crap that you (should have) used for many years in your life just to get through school...

This country is really headed down the shitter

 

[Analog]

WTH is 26+? I'm 43.

 

[imported_yovonbishop]

I got them. I'm 20, been out of high school for 4 years and just took 3.5 years of math in college. Yep.

I imagine if I hadn't been using it in college, I probably would struggle though.

 

[secretanchitman]

im 19 and i can do both long division and multiplication manually.

math was (still is) seriously one of my strong points in high school...luckily, i still retained it during college.

 

[Shawn]

I am 21, and I can do both long division and multiplication manually.

 

[Flash1969]

Originally posted by: jman19

Originally posted by: Flash1969

Originally posted by: jman19
Yeah, division is really useless...

Yes, being able to do it by hand is. Useless to a majority of people.

What if you don't have a calculator or computer near you? This is some really basic crap that you (should have) used for many years in your life just to get through school...

This country is really headed down the shitter

Lol, If you think people not being able to do long division by hand is contributing to this country "heading down the shitter", you are completely out of touch with reality.

Somehow I'm not too worried about running into a "long division crysis".

 

[imported_yovonbishop]

Originally posted by: Electric Amish
No problem @ 35.

Now, if you start asking about differential equations and integration, that's where my memory doesn't serve me as well.

I miss differential equations so much. I actually ENJOYED that class in college.