How many digits?

[R.D. Silverman]

Originally Posted by kokakola

I have taken a number of college level math courses. As others have pointed out, I just didn't make the connection.

Huh? Didn't you study change of base when you studied logarithms
and the exponential function? Surely, when one takes basic calculus,
one learns to differentiate b^x for any b, not just b=e??? This
can't be done WITHOUT understanding how to change bases!!!!!!

[garo]

Bob, please refer to my post in the perpetually pissed off thread
http://www.mersenneforum.org/showpos...9&postcount=15

[R.D. Silverman]

Originally Posted by garo

Bob, please refer to my post in the perpetually pissed off thread
http://www.mersenneforum.org/showpos...9&postcount=15

I'm not flaming here, nor am I criticizing students.
I am criticizing current TEACHING.

The following should be obvious:

" I have a large number. How do I determine its number of digits"?

I would think that to ANYONE who has seen logarithms that
the answer would be obvious: compute its base 10 logarithm.

One also learns the identity (in the appropriate domain) log(x^y) = y log x.


I can't imagine that anything could be simpler. Call it a personal failing
on my part that I fail to see how anyone who has seen logarithms
could not determine the answer.

The underlying difficulty, of course, is that students today only
learn blind manipulation. They do not learn concepts, nor are they
taught how to think; even about something as trivial as this.

The O.P. admitted to taking college math. As I asked: How could
one get through elementary calculus without understanding change
of base for logarithms???

[Prime95]

Originally Posted by R.D. Silverman

I saw all of this,
IN CLASS in the 8th grade. i.e. the last year BEFORE high school.

Fond memories. My Dad introduced me to the rudimentary basics of logarithms when I was in 6th grade. Years earlier he had taught me how to use a slide rule. I finally asked him "why does the slide rule work?"

Now we have calculators and another learning opportunity is lost.

[joblack]

Originally Posted by R.D. Silverman

Huh? Didn't you study change of base when you studied logarithms
and the exponential function? Surely, when one takes basic calculus,
one learns to differentiate b^x for any b, not just b=e??? This
can't be done WITHOUT understanding how to change bases!!!!!!

Please don't be such a 'smartass'. Not everybody read in their teen years math books for entertainment instead of hunting girls ... ;). I think everybody can ask question in a learn friendly environment (e.g. this forum) even if they are 6th grade questions.

[davieddy]

Originally Posted by Prime95

Fond memories. My Dad introduced me to the rudimentary basics of logarithms when I was in 6th grade. Years earlier he had taught me how to use a slide rule. I finally asked him "why does the slide rule work?"

Now we have calculators and another learning opportunity is lost.

Back in them days....

On my 14th birthday, my father (born 1903) gave me and my
younger brother a sailing (racing) dinghy.
For Christmas I got a slide rule (in addition to the usual augmentation
of my Meccano set). I spent Christmas afternoon using it to plot
curves on the graph paper my father always had available.
All my (alcoholic) mother could say was "why don't you put that bloody
thing down and enter the Christmas spirit"
The next Christmas he gave me a Curta mechanical calculator.
Made in Liechtenstein, it cost a bomb an had an action which
was like a Swiss watch.

His equivalent response to "google it" was "look in Chambers
Encyclopedia"

Grades or Years don't impress me much.
At St Paul's, 12/13 year olds started in the 4th/5th form, took
O levels in the 6th form, there was no 7th form, and A/S levels
were the VIIIth form. We had a High Master instead of a headmaster.

Happy days

David

[R.D. Silverman]

Originally Posted by joblack

Please don't be such a 'smartass'. Not everybody read in their teen years math books for entertainment instead of hunting girls ... ;). I think everybody can ask question in a learn friendly environment (e.g. this forum) even if they are 6th grade questions.

Ah yes. Yet another immature idiot resorts to name calling during
a discussion about academic discipline.

Intelligent and motivated people both hunted girls and educated
themselves during teen years. Clearly this does not include you.

[davieddy]

Originally Posted by R.D. Silverman

Ah yes. Yet another immature idiot resorts to name calling during
a discussion about academic discipline.

Intelligent and motivated people both hunted girls and educated
themselves during teen years. Clearly this does not include you.

Lighten up.
I remember fondly a hardware work colleague:
I asked him why something wasn't working and his response was
"I think it's got an attitude problem".

[joblack]

Originally Posted by R.D. Silverman

Ah yes. Yet another immature idiot resorts to name calling during
a discussion about academic discipline.

Intelligent and motivated people both hunted girls and educated
themselves during teen years. Clearly this does not include you.

Great academic teaching does mean more than knowing the topic it means to have the skills to bring the information to the people. Obviously you don't have these soft and teaching skills ... I certainly hope you have no students because I would pity them to have such an humanly unskilled teacher.

Additionally you have no knowledge about my 'women hunting skills' and my 'education' - with your arrogant behaviour it's no wonder you are not a people's person.

PS: If a lot of other people have called you names it's an indication that you're the problem and not the other people (but what I've seen about your behaviour you won't get it anyway)

[flouran]

Originally Posted by R.D. Silverman

I'm not flaming here, nor am I criticizing students.
I am criticizing current TEACHING.

The following should be obvious:

" I have a large number. How do I determine its number of digits"?

I would think that to ANYONE who has seen logarithms that
the answer would be obvious: compute its base 10 logarithm.

One also learns the identity (in the appropriate domain) log(x^y) = y log x.


I can't imagine that anything could be simpler. Call it a personal failing
on my part that I fail to see how anyone who has seen logarithms
could not determine the answer.

The underlying difficulty, of course, is that students today only
learn blind manipulation. They do not learn concepts, nor are they
taught how to think; even about something as trivial as this.

The O.P. admitted to taking college math. As I asked: How could
one get through elementary calculus without understanding change
of base for logarithms???

Why in the hell do YOU give a shit about the OP's mathematical background? You are wasting your time. Spend your time on more useful things, like actually doing math rather than criticizing those of others (have you published any new, actually significant papers in 2009? It seems as though you lost your touch in the mid-'90s). Or you can hunt girls as joblack so eloquently suggested. Or perhaps you can do both. You're never too old to do both

[flouran]

Originally Posted by R.D. Silverman

Of course it is! Change of base is fundamental. I saw all of this,
IN CLASS in the 8th grade. i.e. the last year BEFORE high school.

Solving 2^x = 10^z is fundamental! It is totally trivial.

I studied logarithms in the 4th grade. BFD. The OP SHOULD know logarithms like the back of his hand (since he allegedly stated that he had taken a college course in mathematics), but the OP SHOULD NOT be verbally abused because of his lack of a fundamental concept. He asked a simple question which requires a straightforward answer.