Note: alt.ezines dropped, sci.math added.
Gary Schnabl wrote:
http://groups.google.com/group/misc.education/msg/bed857ef919e3d8f
> I still remember those big trig and log tables in
> high school/college (and beyond) and am glad to not
> need them short of a power failure for my computer
> or missing my "solar" powered scientific calculator.
I've always thought it was interesting that texts
continued to include these tables throughout the 1980's
(and maybe even into the early 1990's), long after
no one was ever using them. Well, *almost* no one.
I sometimes used them to help students understand
certain concepts in a more concrete fashion. For
example, properties of logarithms such as
log(ab) = log(a) + log(b) and log(a^b) = b*log(a)
become more personalized when you spend a few
minutes using log tables to perform a numerical
computation such as the fifth root of 3500 times
the cube root of 260. Also, the rule that
10^log(a) = a gets reinforced when you're using
the antilog tables.
I once gave a talk at a T^3 (Teachers Teaching
with Technology) conference whose theme was a
little antithetical to the party line. One part
of my talk dealt with the topic "What has Technology
Subtracted?", and before giving a number of examples
(such as logarithm tables), I said:
Technology has made a number of previously taught
topics obsolete. Some of these obsolete topics were
useful for their reinforcement of facts that we
wanted students to know very well, some of these
topics were useful for their development of mathematical
thinking, and some of these topics do not appear
to have any significant merit beyond their necessity
before present technology.
I focused on these two areas:
A. Topics that Reinforce Certain Facts
There are several topics that once reinforced certain
mathematical facts, but no longer do so in the presence
of current technology. The impact of these omissions
has less effect on the teaching of gifted students
than on the teaching of average ability students,
since the former require less drill and practice.
Nonetheless, I often encounter very talented students
who display some striking weaknesses. I suspect that
these weaknesses are primarily caused by less drill
due to the omission of these topics.
I discussed "Numerical calculations with logarithm
tables", "Calculating square roots", "Arithmetic
operations with rational numbers", "Estimation,
consistency, and exact values", and then posed
the question: "Do we want students to be as proficient
with these skills as they once were? For those
skills in which the answer is "YES", what should
we include in the curriculum to give our students
the necessary drill?"
B. Topics that Develop Mathematical Thinking Skills
The presence of graphing and symbolic calculators has
turned some problems whose solution once involved higher
order thinking skills into drill problems.
I discussed "Curve sketching" and "Algebraic and numerical
computations". In the latter, I discussed the re-enforcement
of algebraic facts in simplifying numerical computations,
such as rewriting 5*7*11*2 as (5*2)*(7*11) and (3.8 x 10^-7)/5
being evaluated via (380 x 10^-9)/5 = (10)(3

/5 x 10^-9
= (2)(3

x 10^-9 = [(2)(30) + (2)(

] x 10^-9
= 76 x 10^-9 = 7.6 x 10^-

. Then I posed the question:
"How do we compensate for the absence of topics
that once required higher order thinking skills,
but no longer do so?"
> But again, I was schooled in an era when we really
> learned arithmetic and reading text-based material,
> when phonetics education was universal, when being
> taught axiomatic geometry and calculus courses in
> high school/college were the norm, and when we were
> actually taught our non dumbed-down courses by
> competent teachers who weren't constantly bitching
> about not being overpaid enough (and, fortunately
> for those teachers, were not universally dissed).
Without getting into the other things you said,
I disagree with the part about calculus. In the
last 10 or 20 years many, many more U.S. high school
students (as a percentage of the population, even)
have taken calculus than in the decades before this.
My high school didn't even offer calculus (well into
the early 1980's, I think), but they do now. I think
you'll find the number of high school students taking
AP-calculus is far higher in recent years than it
was 30 or more years ago, before calculators were
in general use. Now, the question of whether this is
a good thing or not is another issue, one that is
often brought up by college faculty who have to
deal with students that took calculus in high school
and then wind up not_even_placing_into_precalculus.
By the way, I thought Cary Kittrell's idea (in this
thread) of a calculator that forces students to
determine the power-of-ten order of a computation was
a great idea. I think it has significant potential
(financial and educational), and she should
consider approaching a calculator company about it.
Dave L. Renfro
>> Stay informed about: Calculator Dependence.