Ozzes and Libs

Back in the halcyon days of my youth, it was taken for granted that the US would very soon be shifting over to the metric system from the cumbersome "English" system of measurements then in use, featuring feet and inches, pints and quarts, and as Lucy Van Pelt of "Peanuts" fame put it, ozzes and libs. The forward-thinking teachers at my forward-thinking elementary school prepared us by using Cuisenaire rods to help us think in centimeters and decimeters (a white rod = 1 cm, an orange rod 1 decimeter). Forward-thinking radio stations began giving the temperature in degrees Celsius along with degrees Fahrenheit. (Though giving the Celsius BEFORE the Fahrenheit might have been more successful.)

Even baseball, rarely identified as a forward-thinking sport under any circumstances, got into the act. No, they didn't redefine the distance between the bases as 27.43 meters, or go to ten-out innings and ten-inning games (and a good thing too, ballgames being slow enough as they are), but the forward-thinking Cincinnati Reds posted the distance to the outfield fences in Riverfront Stadium in meters as well as feet, and it seemed only a matter of time before other teams did the same. Yes indeedy, the metric system was on the move.

Well, the metric system may have been on the move, but like Godot and the Robert E. Lee it never quite arrived. True, it's made a few inroads. You can buy 2-liter pop bottles in stores all across the country, for example, and metric is spoken among all scientists--even those from the US. Still, very few Americans think in metric, and the reality is that metric measurements are not a part of very many people's ordinary lives. Like it or not, we still measure the distance to work in miles and the capacity of our gas tanks in gallons. If we hear that the temperature is 28 degrees, we dress our children in coats, not shorts and sandals. When it comes to snow, we know that ten inches is a lot; we're not sure what to make of "254 mm". We buy bologna by the pound and extension cords by the foot. In the race for American hearts and minds, the metric system is behind by, oh, 72.5 kilometers or so.

I won't debate whether this is good or bad (well, I won't debate it today, at least). It does present a bit of a problem for math teachers, however. In Germany or South Korea or Chad or practically anywhere else on the globe, children learn metric measurements; it's simple as that. In the US, we have to teach two systems. We have to teach customary measurements, because that's how Americans measure, and it's how Americans think. We have to teach metric measurements, too, though, because they will be needed for science, because they're in use elsewhere, and because--hey, you never know--we might actually convert to metric someday. So teaching measurements is a trickier business here than elsewhere.

Elementary schools typically deal with this problem by introducing the familiar "English" units first. Then it's time for a brief glimpse at the corresponding metric measurements. Immediately after investigating feet and inches, say, children then spend a short(er) period getting to know meters and centimeters. Then it's on to ozzes and libs, followed by grams and kilograms. And so on. Science instruction helps extend metric understanding, but the bulk of math instruction focuses on customary units. Combined with the use of the English system in everyday life, kids usually come away with a pretty good sense of how long a foot is or what it's like to be outside on a 70-degree day. They don't, however, get the same experience with metric measurements.

That's about how we do it at PDS, too: customary units first, metric in science and as a follow-up. Sometimes I have qualms about this approach. The rest of the world uses metric, after all. Besides, while it's not perfect, the metric system does make logical sense; it's certainly easier to convert centimeters to meters than to convert inches to feet. And maybe my forward-thinking teachers were right, if a bit off in their estimation of time, and the children of today will be using metric units for practically everything when they're adults. Perhaps, I think now and then, we should put less emphasis on miles and more on milliliters.

But the reality is that we already are pressed for time. There's a ton (okay, okay, 909 kg) of stuff to cover in the curriculum, with measurement being only one of many topics worth pursuing. Besides, as long as the metric system isn't in widespread use here in the US, instruction in metric units isn't going to be terribly meaningful to children. There are good reasons for focusing on the units that children hear and see in everyday life. ("See that bird? About 50 meters away?" "Huh?") And so, for now at least, your children will spend a good chunk of their measuring time at school looking at pints and quarts, inches and yards, degrees Fahrenheit, and of course, our old friends ozzes and libs.