wrote in message ...
In article ,
Bill Grey wrote:
"Baz" wrote in message
. ..

What is a venn diagram?

Those of us of a certain age wold not have come across these mystical
designs.

But then I remember "times tables" :-)

Well, yes. But it depends more on your level of education than
your age - after all, I have my doubts that you completed your
schooling before 1880 :-)


Regards,
Nick Maclaren.

It somtimes feels like that :-)

I left Grammar School in 1952 and there had been no mention of Venn diagrams
at that time.

Bill

wrote in message
...
Bill Grey wrote:
But then I remember "times tables" :-)

My 7 year old came home with homework last week where he had to learn his
2
times table. Which was interesting, because although he knew the maths
and
the numbers, he had no concept of the whole "no twos are zero, one two is
two, etc" phrasing/chanting of it.



It is a damned good system and worked well for decades if not longer.

Bill

"Sacha" wrote in message
...
On 2011-01-25 08:57:46 +0000, said:

Bill Grey wrote:
But then I remember "times tables" :-)

My 7 year old came home with homework last week where he had to learn his
2
times table. Which was interesting, because although he knew the maths
and
the numbers, he had no concept of the whole "no twos are zero, one two is
two, etc" phrasing/chanting of it.

When I was about 4 or 5 I went to a small school where we used to chant
our tables first lesson every morning. I know it's considered the 'wrong
way' now (or is it?) but that method certainly made the tables stick in
the mind. To this day, I recall my tables easily.
--
Sacha
www.hillhousenursery.com
South Devon

"If it ain't broke don't fix it" applies I beleive. Why change something
for tha sake of change.

Bill

It matters less now, of course, because there are a variety of ways to do the sums. What is needed is enough mathematical common sense to be able to check that your answer is in the right ball park and that you have entered the formula correctly. I'm delighted that schools are formally teaching estimation methods - I had to work this out for myself.

My son is doing a maths degree, and although they still have to be able to work things out themselves, the availability of calculation aids means they do not need to acquire such fluency. They can spend more time understanding the principles, and investigating more complicated models. Some of his questions are challenging me!

Arguably, knowing ones tables is a lot less important than being able to understand percentages, differentials and probabilities. Often I see articles in the press in which percentages have been translated into fractions which are plain incorrect, hear people mix up "RPI is lower" with "prices are reducing", or see people worry unduly about a "50% increased risk" when the risk itself is so small that the change in behaviour to avoid the risk itself has more ill effects!

I'd happily settle for less ability to multiply numbers together in ones head in exchange for greater understanding of what the numbers actually say, and therefore a greater ability to separate scientific argument from opinion and quackery.

In article ,
Baz wrote:

[ Venn diagrams ]

It's a bad description, anyway. They are the overlapping circles
(or other shapes) that are often used to illustrate set membership.
The area in circle A but not in B represents the elements that
have propert A but not property B, and the area in the overlap
represents the ones that have both properties. And so on.

A bit like a Vector, a mathematical model to prove or disprove a theory?

Yes and no. They are used to demonstrate properties, rather than
prove them. They are more like graphs (in the school sense).


Regards,
Nick Maclaren.

Sacha wrote:
My 7 year old came home with homework last week where he had to learn his 2
times table. Which was interesting, because although he knew the maths and
the numbers, he had no concept of the whole "no twos are zero, one two is
two, etc" phrasing/chanting of it.
When I was about 4 or 5 I went to a small school where we used to chant
our tables first lesson every morning. I know it's considered the
'wrong way' now (or is it?) but that method certainly made the tables
stick in the mind. To this day, I recall my tables easily.

There was a huge difference between how I was taught in my first primary
school (in merseyside) and the one I went to for 18 months when we moved (in
Cambridge).

At my first school, we never really /did/ times tables. They taught us more
the maths behind it, how to work it out, but there wasn't a real emphasis on
maths at all at that school (other than I got some extra lessons by a keen
teacher, cos I was actually 'good' at maths) - there was a lot of emphasis
on English, specifically on reading and comprehension.

At my second school, when I was 10, there was a lot of stuff that I hadn't
learnt which was assumed knowledge. It was really quite bewildering. I
didn't have the instant recall of times tables, but I knew how to get to
them ... so I couldn't do the instant answer to 'what is 6 times 7' (eg -
and I still can't now! 6, 7, and 8 all fox me!), but I could work out the
answer, and I could expand on that to work out /any/ answer, outside of the
1-10 (or 1-12?) that everyone else could.

So I guess what is /really/ needed is a happy medium, where you can use the
instant recall to apply to the more general method, if that makes sense.
Unfortunately there seems to be only so much one can cram into a little
brain at a time!

(perhaps I should start playing times table tapes to the boys at night
instead of the Gruffalo!)

'Mike' wrote:
I went to a Private School and they were very hot on the 3 x 'R's from a
very early age. Later, and as I had no desire to go into the Hotel business
like my parents, I went for an interview for an Apprenticeship as a Marine
Electrical Engineer During the interview I was asked 'What are your Maths
like?' 'Good I suppose', 'What are 7 x 8's?' and before he had finished I
flashed '56'. I always remember that because I surprised myself as to just
how fast I was able to recall it!!!!


My 8 times table is improving ever since work started allocating our leave
in 'days of 8 hours' and a summary of 'how many hours leave you have left'.
So I look at my 56 days left to use by end of March and have to work out
what that is in days!

wrote in :

In article ,
Jake wrote:

To clear up all the confusion, I offer the following copy and paste
from Wikipedia:

"Venn diagrams or set diagrams are diagrams that show all
hypothetically possible logical relations between a finite collection
of sets (aggregation of things). Venn diagrams were conceived around
1880 by John Venn. They are used to teach elementary set theory, as
well as illustrate simple set relationships in probability, logic,
statistics, linguistics and computer science (see logical
connectives)."

I think that explains things perfectly and simply and should serve to
end all further argument.

Ha, ha, very ironic! The first sentence is complete crap. They
show the 'inclusion' type relationships only.

It's a bad description, anyway. They are the overlapping circles
(or other shapes) that are often used to illustrate set membership.
The area in circle A but not in B represents the elements that
have propert A but not property B, and the area in the overlap
represents the ones that have both properties. And so on.


Regards,
Nick Maclaren.


A bit like a Vector, a mathematical model to prove or disprove a theory?

Baz

wrote:
The area in circle A but not in B represents the elements that
have propert A but not property B, and the area in the overlap
represents the ones that have both properties. And so on.
A bit like a Vector, a mathematical model to prove or disprove a theory?
Yes and no. They are used to demonstrate properties, rather than
prove them. They are more like graphs (in the school sense).

In more practical terms, I think they're used to demonstrate demographics,
etc, for advertising + management types

wrote:
On the matter of multiplication tables, I didn't learn mine until
I was well into my teens, and 7x8 was always my bugbear - however,
I could work out the answer fast enough that the teachers never
realised, so I never got punished for it (sic). 7x8 = 2 x 7x4
or 7x8 = 7x7 + 7.

I think I do the last one, (7x7)+7

wrote in :

In article ,
Baz wrote:

[ Venn diagrams ]

It's a bad description, anyway. They are the overlapping circles
(or other shapes) that are often used to illustrate set membership.
The area in circle A but not in B represents the elements that
have propert A but not property B, and the area in the overlap
represents the ones that have both properties. And so on.

A bit like a Vector, a mathematical model to prove or disprove a theory?

Yes and no. They are used to demonstrate properties, rather than
prove them. They are more like graphs (in the school sense).


Regards,
Nick Maclaren.

LOL, Nick, nice one.
It is surely a LOOONG time since you got your "degree in mathematics"

You obviously did your dissertation on the subject of how to be a knowall
and yet know very little (in the school sense).

I think you mean arithmetic.

Regards
Baz

In article ,
kay wrote:

Arguably, knowing ones tables is a lot less important than being able to
understand percentages, differentials and probabilities. Often I see
articles in the press in which percentages have been translated into
fractions which are plain incorrect, hear people mix up "RPI is lower"
with "prices are reducing", or see people worry unduly about a "50%
increased risk" when the risk itself is so small that the change in
behaviour to avoid the risk itself has more ill effects!

I'd happily settle for less ability to multiply numbers together in ones
head in exchange for greater understanding of what the numbers actually
say, and therefore a greater ability to separate scientific argument
from opinion and quackery.

That is true mathematical wisdom - seriously!

Nowadays, someone who has trouble with elementary arithmetic can
always carry a calculator - and one is built into many mobile
telephones and even watches.


Regards,
Nick Maclaren.

Martin wrote:
So I guess what is /really/ needed is a happy medium, where you can use the
instant recall to apply to the more general method, if that makes sense.
Unfortunately there seems to be only so much one can cram into a little
brain at a time!
In real life being able to instantly recall a product is better than knowing how
to derive it from scratch.

I totally disagree. If the 'instant recall' is outside of the small list
you have learnt, it's pointless. You need /both/ to be most effective.

(perhaps I should start playing times table tapes to the boys at night
instead of the Gruffalo!)
I learnt mine in the bath.

I remember 'completing the square on a generic quadratic from first
principles' suddenly clicking whilst I was in the dentist chair having a
tooth removed ...

wrote in message
...
Martin wrote:
So I guess what is /really/ needed is a happy medium, where you can use
the
instant recall to apply to the more general method, if that makes sense.
Unfortunately there seems to be only so much one can cram into a little
brain at a time!
In real life being able to instantly recall a product is better than
knowing how
to derive it from scratch.

I totally disagree. If the 'instant recall' is outside of the small list
you have learnt, it's pointless. You need /both/ to be most effective.

(perhaps I should start playing times table tapes to the boys at night
instead of the Gruffalo!)
I learnt mine in the bath.

I remember 'completing the square on a generic quadratic from first
principles' suddenly clicking whilst I was in the dentist chair having a
tooth removed ...


I wonder if there are any Electronic Engineers reading this who remember the
mnemonic for remembering the Resistor Colour Code ;-}}

Of course you do, but are toooooooooooooooo polite to post it here ;-)

Mike


--

....................................
Don't take life too seriously, you'll never get out alive
....................................


Mike