The metric system and USA

July 2004

Abstract:
American school children spend countless hours mastering the antique English system of measurement – without ever mastering it. Foreign children who use the metric system can instead spend their time learning the actual subjects.

The practical advantages of the metric system (also known as "ISU" – or "SI" – for "international system of units") are so well known that I won't beat that dead horse. But let's look at the educational advantages of the system, something that has not been sufficiently considered in the U.S. Let's follow two students, Ingrid in Norway and Sue in the U.S., as they study their own country's measuring system. It's an early fall day at the beginning of the school year.

Both teachers start out, "Good morning, students! Today we're going to learn about lengths, or distances." But here, the two students hear rather different things:

DISTANCE MEASURE:

Ingrid (in Norway) hears: Here is a "meter stick." Meter means "measure", and this stick is our unit of measure; it is one meter long. We can divide this meter into a hundred parts; these parts are called centi-meters because "centi" means a hundredth. We can divide each centimeter into ten parts, which are then each a thousandth of a meter; these are called milli-meters because "milli" means a thousandth. A length of 10 cm is called a "decimeter", one-tenth of a meter. When we want to measure long distances we use a measure of a thousand meters and call that a kilo-meter because "kilo" means thousand. Now, how many centimeters would there be in a kilometer? That's right, Ingrid, 100 times 1000, or 100,000. For homework, please learn these four prefixes. They'll become old friends because we'll use them again and again.      (Now Ingrid knows about everything she needs to know about calculating with distances, and it's just a matter of a little practice: Need to divide 8 ½ meters into five equal segments? OK. 8.5m / 5 = 1.7m or 1m 70cm. Piece of cake.)

Sue (in the U.S.) hears: Here is a "yard stick." It is our unit of measure; it is one yard long. We divide the yard into three equal parts; each is called a "foot." We divide the foot into twelve equal parts, and each of these is called an "inch." There are 36 inches in a yard. When we want smaller parts we divide the inch into sixteenths; these are simply called sixteenths. There are 192 sixteenths in a foot, and 576 sixteenths in a yard. We can also divide the sixteenths in half so that we have 32ths, and again to get 64ths. When we want to measure long distances we use a measure called a "mile." A mile is 1,760 yards, or 5,280 feet. Now, how many inches would there be in a mile? No one...? Well, there are obviously 63,360 inches in a mile. For homework, please see how far you can get with this mess. Just remember, sixteen "sixteenths" to an inch; twelve inches to a foot; three feet in a yard, and 1,760 yards in a mile. Good luck!      (Now Sue is all confused. Let's see: divide 8 ½ yards into five equal segments? OK. 8.5yd / 5 = 1.7yd. But what's ".7yd"? Maybe if we turn it into inches? One yd is 36 in. so .7yd is 36in x 0.7 = 25.2in. But we don't use 10ths of inches, so how many 16ths would 0.2in be? Uh, 16sixteenths x 0.2 = 3.2 sixteenths. But there's still that 2/10 of a sixteenth. What do I do with that? Nuts! A big part of the problem is of course that our number system is decimal, but the units of measure she is being taught are not!)

AREA MEASURES:

(It's the next week in class. Ingrid has the simple metric measures down cold. Sue is still struggling to memorize last week's seemingly unrelated numbers.)

Ingrid learns what a square meter is: A square, one meter – 100 cm – on a side, or 10,000 cm². To measure large areas, like plots of land, we use a square of 10 meters to a side called an "are", or 100 m². For really large areas we'll take 100 m on a side, or 10,000 m², called a "hectare" ("hect" means a hundred, and a hectare is a hundred ares). For map-sized large areas we can use square kilometers. There are of course 100 hectares, or a million m², in a km². Piece of cake; just add zeros.

Sue learns that a square yard is one yard – 36 inches – on a side, or 1,296 in². A square foot is 144 in², and there are nine square feet to a square yard. For large areas we'll use the "acre", and for really large areas the square mile. Now, since the mile is 1,760 yards, it's plain that a square mile is 3,097,600 square yards, or 27,878,400 square feet. No, Sue will never learn that; hardly any American child would know this. Now, the acre is a more convenient areal measure for house lots and the like. And it's not too hard for Sue to learn that there are 640 acres to a square mile. Well, actually almost 640 acres. It's actually 639.9974 acres, because the measures of "acre" and "square mile" have no direct connection. An acre, by the way, is also 4,840.019 square yards, or 43,560.17 square feet. Sue will never learn these conversions, either. In fact, for Sue to learn to convert any measure of area to any other she'll probably have to find a book and look it up.

VOLUME MEASURES:

"And today, children, we'll learn about volumes, or three-dimensional space." The Norwegian teacher continues, "This will be very easy because you already know almost everything you need to know to understand it." (I'm not sure how the American teacher introduces this dreaded subject.) Both teachers explain that we use two forms of volume measurement, one of them usually reserved for liquid measures. Their task is now to explain the connection between the two.

Ingrid learns how we calculate and convert cubic meters, decimeters, centimeters, millimeters, etc. Very straightforward, of course, since it's just a matter of adding zeros. But how about the liquid measures? Well, here's a "liter" bottle. Guess what? It holds the same as a cube with 10 cm on each side. In other words, it's a cubic decimeter, or dm³. Therefore there are as many liters in a cubic meter as there are cubic decimeters: One thousand. How neat! And a tenth of a liter is of course a deciliter, a hundredth is a centiliter, and a thousandth is a milliliter. Ingrid could tell all that right away, by the prefixes.

But Sue... She has absolutely the same talent as Ingrid, the same ability to learn. But our American society seems to conspire against her. She's expected to learn something like this: Our usual dry measure is the cubic foot, which contains 1,728 cubic inches. There are 27 cubic feet, or 46,656 cubic inches, in a cubic yard. Tough enough, but now let's learn the liquid measures: Here we use the good old "gallon". The gallon is, for some reason, 231 cubic inches, so we can pretty much forget about making that conversion. But the gallon system has its own logic: We divide the gallon into four "quarts" which are again divided into two "pints" which are divided into two "cups". Thus there are 16 cups to a gallon. Of course there's no reasonable relation between a cup and a cubic inch. (For the curious, it's 14.4375 in³ per cup.) Now, we also divide the gallon into "liquid ounces" and there are 128 oz in a gallon, 32 oz in a pint, and 4 oz in a cup. The (liquid) ounce is therefore 1.804688 cubic inch. Very neat, eh, Sue?

Enough said, really, but let's add, to wrap up, that the related measure of weight (or mass) presents exactly the same picture. The American child is presented with the same maze of nearly unrelated units: The pound, the ounce (a different ounce!), the ton. Children in most of the rest of the world enjoy the beauty of the metric system's milligrams, grams and kilograms. The metric system even connects with the most essential compound for human life: Water. One liter of pure water weighs one kilogram. It also connects with the Celsius temperature scale, where water freezes at zero degrees and boils at a hundred. And with the definitions of heat (measured as the heat energy needed to raise one gram of water one degree C), force, power, energy, pressure, density, flow, ... with meteorology, biology, physics... in fact, with everything having to do with science and with technical communication around the world.

Why do we do this to American children?  Why do we make them waste their valuable school time on the long outmoded English system, this diabolical mish-mash of irrational and unconvertible units, while children all around the world are learning a simple and logical system which is not only easier to use later in life, but saves their study time for useful learning? Why do we befuddle our children's minds with such trash, which seems designed to make them rebel against learning as an arcane and unpleasant chore. Why make them spend ten times as much time on learning a system which is not a tenth as good? We handicap our kids from the start with this byzantine system, and it's way past time to abandon it and join the rest of the world.

The English system of measurement had its use in its day, but it is now a legiron on American society. The irony is that the industrial leaders who have campaigned with such vigor to oppose introduction of the metric system are among those who stand to gain the most from the improved education and communication and the competitive enhancement that would come from tossing off the chains of the English system and placing ourselves on an equal footing with other modern societies.