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# The Case for U.S. Metric Conversion Now

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The news by now is familiar and expected. U.S. elementary and high school students perform poorly in comparison with their foreign counterparts on international tests of mathematics and science achievement. Several explanations have been posed to explain the poor performance, such as a relatively shorter school year in the United States, fewer required math and science courses in U.S. high schools, sub-populations taking the exams that differ from country to country in the proportions of students at each grade level represented, and (need I mention it?) inferior schooling.

I'd like to pose another possible explanation. The United States, almost alone in the world, does not use the metric system of measurement in its daily life. But it does teach the metric system in the schools. It teaches two systems of measurement in the schools and, the confusion from learning two systems aside, there is a cost to the time spent in teaching two systems. A full year of mathematics instruction is lost to the duplication of effort.

Mostly in the elementary grades, our schools spend a few weeks a year teaching two measurement systems when teaching just metric could be done in one-third the time. Elementary school mathematics textbooks generally give equal weight to the two systems, as do the newly completed curriculum standards of the National Council of Teachers of Mathematics. Educators feel forced to teach both systems because, even though we Americans still use the inch-pound system in our daily lives, the metric system is used in many professions (medicine, science, and engineering, for example) and now in much of industry. High school science courses now use the metric system exclusively.

The year's worth of classroom time savings would accumulate from several sources, including: elimination of the duplication of teaching two systems; the conciseness of the metric system, which requires much less time to teach and in which calculations can be performed more than twice as quickly; and a reduced amount of time devoted to teaching fractions.

Teaching the metric system in the schools would be of little help to our students, however, if the society in which they live continues to use the inch-pound system. The solution is to implement a nationwide "soft'' conversion to the metric system. This would involve dual labelling of all measured items used publicly, such as many consumer products and highways. Dual labelling would enable all adults familiar with the inch-pound system to continue using the inch-pound system at the same time students who learn the metric system could fully function in society using their metric knowledge.

It should be emphasized that, beyond obliging firms and public authorities to provide dual labelling, no one would be forced to do anything. No adult would be forced to learn the metric system. No company would be forced to size its products in metric, or retrofit equipment to metric sizes. The conversion of products and equipment to metric sizes is happening anyway, albeit very slowly, and most quickly in those firms involved in international buying and selling. And, sensible exceptions should be made even to the dual-labelling requirement--on football fields and in hardware stores, for example.

Soft conversion to the metric system might cause some inconvenience to adults as they get used to dual labelling on highway signs and in public places. And perhaps careful effort should be made to clearly distinguish the metric numbers from the inch-pound numbers, by using different colors or different scripts, for example. But the inconvenience would be slight. Think of how effortlessly we got used to the labelling on the many consumer products that are already dual-labelled.

The benefits could be enormous. Though it would cost some money to redo signs and labels nationwide, the one-time-only cost amounts to only a few hundred million dollars. By contrast, we spend over one-and-a-half billion dollars per year as a nation for a year-long mathematics course in the public schools. With another year of mathematics, our students could either learn their math a lot better, or take a second year of algebra or a year of geometry, statistics, or economics. And, they should be able to perform much better on those international math tests.

One may vaguely recall that metric conversion in the United States was already tried once, and failed. There was a plan in the late 1970's to convert, at about the same time as Canada did. The U.S. plan met some opposition, the most colorful coming from some unapologetic luddites and xenophobes. (The xenophobes were somewhat misinformed. The inch-pound system is really of British, not American, derivation, and the British themselves abandoned it in favor of metric years ago.)

The few serious studies of metric conversion at the time did not attempt to measure the benefits and costs of conversion. They merely asked firms in various industries how they felt about conversion, and the responses were more unfavorable than favorable. The intervening years have shown, however, that metric conversion in industry, when it is done as part of the normal product-replacement cycle, is far less expensive and disruptive than had been feared.

The studies did not attempt, in particular, to estimate the savings in classroom time that a metric conversion would effect, nor did they anticipate that our schools would be stuck with both systems of measurement in their curricula. Neither did the studies consider the possibility of a soft conversion plan, such as I have described.

Most everyone favors technological advance. Metric conversion offers one that is simple and familiar. Just about every other country in the world has adopted it. Yet, despite its simplicity and familiarity, the benefit of this technological advance can be very large. To fully know an inch-pound system consisting of 12 measures requires memorization of over a thousand different names and conversion ratios. A metric system of equivalent size includes only 36 names and conversion ratios, and all calculations can be done more simply in decimal notation.

Progress involves not only adopting new, more efficient technologies, but an ability to recognize when and which new technologies are superior and a willingness to let go of old, less efficient ones. And, some progress inevitably requires collective effort and government action.

Richard Phelps works as an analyst on education issues in the U.S. General Accounting Office in Washington. He formerly taught middle and high school mathematics in the West African nation Burkina Faso. The views expressed here are his own and should not be construed to be the policy or position of the U.S. General Accounting Office.

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