CALCULADORAS GRÁFICAS Y LA CIENCIA.
In recent years, new kinds of calculators have begun to appear in secondary schools, especially in mathematics departments. These calculators are commonly called 'graphics' calculators (or some variation on the adjective), because they have a small graphics display screen rather than the one-line numerical display that wehave been used to with hand-held calculators. The appearance of these devices in schools has been hastened considerably by the official approval of their use in the TEE from the 1998 examinations in all mathematics subjects and also in some science subjects. It would be a mistake, however, to make the inference that these devices are mainly useful for examinations. Rather, the official TEE sanctionis an acknowledgment that examination prohibition hampers the use of appropriate technology in schools.
Although they are relatively new to WA, having first appeared in class-set quantities in schools about six or seven years ago, graphics calculators can hardly be described as a 'new' technology. For example, they have been on sale to the general public in USA since 1985, and have been inwidespread use in high schools for a decade. Similarly, they have been available in schools and used in A-level examinations in the UK since the late 1980's. The machines on sale today are arguably the third generation of graphics calculators. There are four manufacturers at present, each a familiar multinational company. In alphabetical order, they are Casio, Hewlett Packard, Sharp and TexasInstruments.
The main uses of graphics calculators are for students learning and doing mathematics. However, in Western Australia, it is almost always the same students learning both science and mathematics. So, we can expect that almost all science students in upper school will have an increasing level of access to a graphics calculator in the near future, and that many students will own their own model.Even in the lower secondary school, the most likely scenario for the near future is that a graphics calculator will become standard equipment for most students, instead of the scientific calculator. Although many schools continue to ask students to purchase a scientific calculator early in secondary school, the decreasing price of graphics calculators (the least expensive now around $60 tax exempt)are likely to encourage a rethink of this practice, to reduce the risk that students will need to purchase more than one calculator over their secondary schooling years.
This paper suggests some graphics calculator capabilities that may be of interest to science teachers, with the emphasis on student learning rather than assessment.
A better scientific calculator
A graphics calculator is,first of all, a calculator. That is, it can be used to calculate things for which students presently use a scientific calculator; in fact, it is a good substitute for a scientific calculator, rather than a device that one would use together with a scientific calculator. (Incidentally, I confess to being mystified as to the origins of the adjective 'scientific' used to qualify a calculator. There isnothing at all scientific about its operations, and it is no more likely to be used for science than it is for engineering, mathematics, accountancy, statistics, economics or architecture. I can only guess that it was a form of marketing ploy.)
The graphics calculator is a good substitute for a scientific calculator because it does the same kinds of things better and because it also does otherthings too. To illustrate these claims, consider the four screens below, electronically taken from a Casio cfx-9850G calculator.
Notice first that each screen shows that what is entered into the calculator stays on the screen, so that any punching errors can be detected. This allows students to check that they have calculated what they intended to calculate, rather than repeating the entire...