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1994 Book DidacticsOfMathematicsAsAScien
some, but less for all due to the advances that those few make. Just as we
use algebra to solve problems that the ancient Greeks solved or attempted to solve geometrically, and even many of us in mathematics have never lear- ned how they did that, it is possible that future generations will learn how to use the latest technology to solve our algebra problems, and never learn how we did it using algebra. ZALMAN USISKIN 321 MATHEMATICS FOR ALL The situation in algebra is made more interesting by spreadsheets, which have their own algebra. Possibly, in the near future, the language of spread- sheets will become the most commonly used algebraic language. Thus it may be that the algebraic language everyone comes to learn is a different one than the one historically taught in schools. The difference between al- gebra in school and algebra in the real world would seem to be akin to the difference between arithmetic in school and arithmetic in the newspaper. In school, the tendency in almost all countries is to concentrate on the Skills and Properties of algebra, while in the world at large, the Uses predominate, with Representations also being quite important. The same technology that enables algebra questions to be treated without algebra also enables calculus questions to be treated without calculus. The very same software programs and calculator technology that enable one to avoid symbolic algebra also make it possible to avoid the symbolic manipu- lations of calculus and statistics. It is possible today to answer max-min problems without having to resort to derivatives; to obtain areas under cur- ves without integrals. In many places we have justified algebra not on its own merits but on its importance in the more advanced mathematics of cal- culus and differential equations. But, with technology, these subjects, too, are not so advanced. We must be careful that, despite its importance, we do not lose algebra in school because of the other means we now have for tackling problems that used to be algebra. 9. CAN ALGEBRA AND CALCULUS CONCEPTS BE LEARNED? In many countries, the national curriculum includes a study of algebra for everyone, a trend that is gaining favor in the United States (NCTM, 1990). Yet, even in those countries, many of the algebra teachers believe algebra cannot be learned by all. The argument that I heard on a visit to schools in Shanghai was the same as the one I hear in my own community: Students can all learn to do algebra, but they do not all understand what they are do- ing. Many more teachers think that calculus cannot be learned by all, for the subject matter itself is beyond the students. If these subjects do not change both in the classroom and in the society at large, I agree with this point of view. Courses taught as exercises in formal structure do not have a broad enough base of appeal to become more than mechanics. If we teach only mechanical skills, we should not be surprised that our students learn only mechanical skills! But all of the current devel- opments suggest that "algebra for all" will be quite different from the tradi- tional algebra that we have been teaching, and I believe that it will include calculus. The reason for my optimism can be found in any country where our lan- guage is not the mother tongue. When students begin learning a foreign lan- guage in senior high school, so that they are studying that language at about the same time that they take algebra through calculus, as in the United 322 ZALMAN USISKIN States, they usually have a great deal of trouble learning it. Their accents are atrocious, it seems as if the language is beyond them, and only a small per- centage seem to do well in their language study. Yet where the language is spoken, even younger children understand, read, and speak it well. Of course, students' proficiency in their mother tongue is not due to any special brilliance, but because they are immersed in it and so become fluent in it. With instruction, virtually all of them learn to decode the multitudi- nous combinations of letters and other symbols that constitute their own written language. It is difficult to believe that any person who can learn to read and write and comprehend his or her native language does not possess the ability to read and write and comprehend algebraic symbolism, part of the language of mathematics. But the ability to learn does not guarantee the realization of that ability. What makes it possible for children to learn languages is an environment in which these languages appear in context. Good foreign language teachers try to imitate this reality. For example, throughout the world where French is not spoken, the effective teacher of French tries to make the classroom into a bit of Montreal or Paris. The movements within mathematics educa- tion to put context into the mathematics, to utilize applications of mathemat- ics in everyday teaching, and to engage students in classroom discussions, can be seen as an attempt to speak the language of mathematics in the class- room. These are the Uses of the SPUR characterization of understanding of mathematics. Since mathematics beyond arithmetic is not yet commonplace outside the classroom, this is a necessary move within the classroom if we are to achieve higher levels of mathematics performance for all. Because mathematics is so much a language, it seems reasonable to con- clude that many aspects of it are better learned when the child is younger than when the child is older. Another reason for the difficulty of calculus is probably because its ideas are often first encountered at ages later than the optimal ages for learning a language. 10. FROM ALGEBRA/CALCULUS FOR SOME TO ALGEBRA/CALCULUS FOR ALL In the future, the algebra-calculus sequence will give less attention to alge- braic techniques when solving problems, because these will be able to be done by hand-held machines and preprogrammed software. But the se- quence will need to have increased emphasis on two aspects of algebra: the uses to which algebra, functions, and calculus can be put; and the impor- tance of algebra as a language for communicating generalizations and func- tional relationships. Both of these aspects increase in importance because of computers. In the parlance of the SPUR characterization, algebra of the fu- ture will undoubtedly contain less of the Skills dimension and more of the Uses and Representations dimensions. The Properties dimension, due to the importance of the language of algebra, is likely to maintain its role in the 323 curriculum. In particular, the broad properties of functions, of matrices, and of vectors will probably enter the domain of mathematics for all. Critical in all this is that the use of algebra as a language of communica- tion be encouraged. In addition to the current emphasis on variables in for- mulas and variables as unknowns, greater emphasis is needed on the uses of variables to generalize patterns, the use of variables as indicating places in spreadsheets or computer storage, and the use of variables as arguments in functions. This could be done in many ways, for example: (a) emphasize how much easier it is in many circumstances to apply a formula rather than read a table; (b) demonstrate how the language of algebra and functions and matrices and vectors makes it easier to handle certain problems; (c) show how some patterns and trends can be described algebraically more com- pactly than with graphs; and (d) show the power of functions to predict, and how picking the wrong function can lead to errors. 11. GEOMETRY FOR ALL? Although in school geometry, students are taught as if the only planar sha- pes are polygonal or circular, and the only 3-dimensional shapes are spheri- cal, cylindrical, or conical, every object in the world, from the chair you may be sitting on as you read this paper to the leaves of a tree considered individually or as a set of leaves, has a shape and a size. Computer graphics have greatly increased our ability to draw pictures to represent this world and to examine those pictures. They have made the Skills and Uses of geo- metry more accessible, and, as mentioned earlier, they have increased the importance of geometrical Representations of functions. The world is geo- metric. Indeed, one could argue that the world is more obviously geometric than arithmetic. Perhaps that is the reason why deductive reasoning came to ge- ometry before arithmetic or algebra. But despite this, the geometry curricula of countries differ more than the curricula in any other area of elementary mathematics (Travers & Westbury, 1990, p. 207). As a result, it was very difficult to assemble the geometry items at the 8th-grade level for the Sec- ond International Mathematics Study (Robitaille, 1989) The theorems of Euclid that dominate some curricula have been replaced with transformation and vector approaches in others. Consequently, though all students today learn some geometry, they do not learn the same geometry. The situation might be characterized as "some ge- ometry, but not the same geometry, for all." Unless there becomes some sort of worldwide standard, it is difficult to believe that this situation will change (see, also, Usiskin, 1987). The situation with respect to geometric representations is quite different. Coordinate graphs and displays of data (bar graphs, histograms, circle graphs, etc.) are reasonably universal, found in newspapers and popular ma- gazines, and their status has become much like arithmetic despite their rela- MATHEMATICS FOR ALL 324 tively short history (bar graphs and line graphs are barely 200 years old; see Tufte, 1983). They have become a part of literacy, found in social science curricula as often as in mathematics. Only the first of the three reasons gi- ven in section 4 above seems to apply here; the societal need to transmit in- formation and the power of a visual display to do so. It seems likely, then, that sets of points will play an ever increasing role in the curriculum, but these may not be the traditional sets of points of Eu- clid, but more ordered pairs and triples, graphs of functions and relations, and representations of graphs and networks. If this is the case, the impor- tance of coordinates and transformations will increase, and the traditional work with polygons and circles is likely to decrease or to be encountered by students earlier in their mathematics experience. 12. MATHEMATICAL SYSTEMS The traditional role of geometry as a vehicle for displaying a mathematical system is already gone from many countries, and there does not seem to be much call for its return where it has left. Moreover, it does not seem that other parts of mathematics have picked up this loss. Less and less formal deduction is being taught in school mathematics courses. Computers present particular problems to those who favor more work with deduction. Because of their ability to display example after example, computers encourage induction as a valid method of argument. Picture a tri- angle with its medians drawn. A student who is able to continuously deform this triangle on a screen, and who sees that the medians are still concurrent, will surely be less likely to think that a written demonstration of the concur- rency is needed. Similarly, a student who can zoom in on the graph of a function to determine its maximum value to virtually any desired accuracy is not likely to see calculus as being as powerful as previous generations saw it. For this reason, the current condition in most countries, in which formal deduction is taught only to some, is not likely to change. Formal de- duction may even be taught to fewer students in the future. These developments reflect a fundamental problem for mathematics edu- cation. The requirement that results be deduced in order to be valid is one of the fundamental characteristics of mathematical thought; it is too important not to be taught to all. Yet it is imperative to take advantage of the power of technology to experiment with mathematics and thus to conjecture from ex- periments. Nevertheless, to go through school mathematics and do many ex- periments but have little experience with proofs is like going through sci- ence education with little attention to experiments but much experience de- ducing from assumed principles. To avoid proof – even to de-emphasize it – would seem to do a disservice to the discipline of mathematics. ZALMAN USISKIN 325 MATHEMATICS FOR ALL 13. SUMMARY We are in an extraordinary time for mathematics, a time unlike any that has been seen for perhaps 400 to 500 years. The accessibility of mathematics to the population at large has increased dramatically due to advances in tech- nology. These advances make it likely that more mathematics than ever be- fore will become part of the fabric of everyone's education and everyday lit- eracy. But the mathematics will not be a superset of what is taught today, for those things that can be done quickly and easily by computers are very likely to disappear from the curriculum. What will remain will probably be a more conceptual and more applied and more visual mathematics. REFERENCES American Association for the Advancement of Science (1989). Science for all Americans. Washington: AAAS. College Entrance Examination Board Commission on Mathematics (1959). Program for Download 5.72 Mb. Do'stlaringiz bilan baham: |
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