One of my students was having trouble with some math exercises (as in, 480 cm. = __m) and I asked him to show me about how long a centimeter is, and how long a meter is, but that was hard for him because he didn’t have an intuitive sense of the relationship between meters and centimeters.
I suspect that the metric system would be much easier for me to teach if it was used here in the US, like it is everywhere else. Instead, kids only see it in math problems, and they never use it for anything practical. Parents are confused by it, since it’s not used outside the academy. In 1975 the US began a gradual and voluntary conversion process that was never embraced by private industry. What we have now is a hodgepodge of metric applications.
To date, there are only 3 countries in the world that have not adopted the metric system – Myanmar, Liberia, and the United States. Resistance in the US, these days, seems to be both nationalistic (“I’m not one for change. I like everything American. If it’s here, it should be American.”) and cultural (“Peter Piper would have had to pick 7570.8 cubic centimeters of pickled peppers.”).
I got curious about the history of the metric system, and the Australian conversion process stands out as an example of systemic change that anticipated and responded to public reactions. The key points I see in the account of Australia’s experience (paraphrased):
- No industry or group was asked to involuntarily implement a program.
- The Act contained no penal clauses.
- Public education by involvement in day-to-day transactions was the focus, rather than instruction by more formal methods.
- Conversion took place in all directions simultaneously.
- People didn’t care about the “logical nature of the metric system or the unsystematic nature of the imperial system,” so the government focused on providing a new set of metric benchmarks and avoided irrelevant references to the elegance of the metric system.
This sounds like an embrace of constructivist epistemology, which strikes me as unusual for official State policy, here in the US, anyway. Execution of the conversion process recognized the need for people to gain an intuitive sense of the new system through experience, not didactically. It happened simultaneously in retail, industry, construction, government, weather reporting, and sports.
Personally, when I write on the Internet, I’m self-conscious about making references to units of length, weight, temperature, and so forth. It’s awkward. Not only that, but as the economy becomes increasingly globalized, it seems reasonable that we’d want to “go the distance” and use common references as much as possible. There are rich discussions about metrication (a new word for me) here and here.
I wonder what anyone else might have to say about whether “going metric” might simplify math education, and what observations people outside the US have of our anachronistic units of measurement.
11 Comments
In Canada, the metric system was implemented gradually while I was in school – first distances and temperatures, then weights and measures. The parts that were used, I learned. the parts that were not yet in use, I didn’t learn. The result is that my intuitive sense of measurement is a mixture of the two:
- temperatures – I understand Fahrenheit, but if asked, will always respond with a Celsius temperature, and it bugs me when weather maps (eg., from Weather Underground) are all in Fahrenheit, so much so that I only use Environment Canada online weather maps.
- distances – kilometers only. I understand miles, but they’re too long. Driving 100 km in an hour is something that makes sense to me. Shorter distances? Meters. There’s a large grey area there – I don’t have a good intuitive idea 0f 20 feet or 60 yards, whatever. And please don’t give me a length in ‘football fields’.
- height – feet and inches. I know I’m just a hair under 6 feet. No idea what that is in centimeters. When I’m measuring wood for carpentry, I will use both inches and centimeters – whichever way the ruler is facing, I don’t care.
- weight – pounds and tons. I know a kilogram is 2.5 pounds. But I don’t know how many kilograms I weigh (I’d have to calculate it). I know what a gram is, but I don’t use grams any more. There’s 28 grams to an ounce. But I don’t really know how heavy an ounce is.
- liquid measures – don’t ask me what a fluid ounce is, I have no idea. I understand liters. Quarts are like liters, only a bit bigger. I know gallons, but I never have enough of any fluid to actually have a gallon of anything. Yet, when describing fuel efficiency, I only understand miles per gallon – 8 is bad, 40 is pretty good. I haven’t a clue what liters per 100km looks like. What is bad? I don’t know. 5?
- land – acres and square miles. But, mostly,. acres. Because we had a 1 acre lot when I was a kid. And the land where I lived was divided into quarters (160 acres), 4 of which made a square mile. That’s what I believe, anyways. Hectares? Funny square acres.
- energy – my mother dieted so I understand calories. Only in theory, however. I actually had to look up a couple of weeks ago how many calories people should consume in a day, 2000 – 3000. Which makes 60 calories good, 400 calories bad. Unless you’re starving, in which case good and bad are reverse. The equivalent in joules? Please, I don’t even know where to begin. That said, I consume power in watts and kilowatts, and pay for it by the kilowatt hours. Every appliance is compared to my gold standard, the 2500 watt hair dryer I bought as a kid. Horsepower? No idea what that is. Cars have, what, 12?
- pressure – I read a lot of science fiction, so I understand ‘one atmosphere’. Kilopascals? Forget it. Millibars? Forget it. For pressure, I understand ‘low’ and ‘high’. For my bicycle tires, I use PSI – but I had to look up a few months ago how many PSI to fill my tires (65). How many PSI is the atmosphere? Not a clue.
Personally I tried to translate all the dates on my blog posting into the Muslim calendar, but that pissed off my one Jew and Chinese reader. I figured I had zero Muslim readers so I stuck with the archaic Christian system.
Where I started primary school in 1971, my year level were the first to be taught only the metric system from the start of their schooling life so I’ve never been taught or even really understand the Imperial system. I do remember that my first wooden ruler had 30 cm on one side and 12 inches on the other to help those older students who were changing to the new system mid-education. To this day, the only way I can visualise feet is by imagining rulers end to end! I remember the changeover to the kilometre signposts and I never did get to really work out how far from the town our farm was (my dad said we lived five miles but that could’ve meant anything to me as a kid!). Other Imperial references of our neighbourhood was the Three Chain Road on the way to Booleroo Centre (where I was born in Imperial 1966) so named for its width. And I do remember my parents buying a 1972 Chrysler Valiant Ranger with both mph and kmh on the speedometer but six years later when they bought a later model Valiant, only the km/h markings remained. So to me, feet, inches, Fahrenheit, acres is all stuff from my parents’ era – one of my father’s favourite news clippings from the Stock Journal in the 1970’s included a Farmer’s lament which roughly paraphrased moaned that the metric system had shrunk his farm, reduced his rainfall and left him a longer drive into town!
As a middle school math teacher, I can say that “going metric” probably would simplify math education. I was thinking about this yesterday when my 7th graders had to measure the sides of some rectangles and divide them in order to find out how many times bigger one was than the other. Most kids chose to measure with centimeters…it’s easy to read on the ruler that something is 7.6cm long, for example. One student was trying to work in inches and was having trouble realizing that the 5th mark on the ruler did not mean 0.5 inches, but rather 5/16 of an inch. Moreover, dividing the measurements is much simpler if you’re working with decimal centimeters than fractions of an inch.
This is a small example of how working with imperial units makes things a bit more complicated than working with metric units. We can have valuable mathematical discussions with our students about working with imperial units and inch rulers, because there are a lot of important ideas about proportions and fractions involved there. However, in a lesson where this content was tangential to the main idea of the lesson, using imperial units just made life unnecessarily complicated.
In an era where kids actually are expected to know more math than ever before (despite what the critics say!), time is at a premium in the math classroom. Not having to worry about imperial units would leave more time to work with other, more important mathematical ideas. I don’t foresee the U.S. going metric any time soon, however, so we math teachers and our students will have to continue dealing with imperial units for the time being.
It occurs to me that a similar phenomenon exists with learning languages. English spelling conventions are so bizarre and irregular that a lot of educational energy is spent learning them. I doubt that students in Spanish-speaking countries have to spend an equal amount of time learning how to spell in Spanish, since the conventions are much simpler.
Doug, you make an excellent point when you note that the only place where students see metric measurements is in the classroom. If they saw the height of their favorite basketball player in meters instead of feet and inches, they would catch on more quickly.
If you’re interested in metric trivia: Interstate 19 in southern Arizona, which runs between Tucson and the Mexican border, is signed in kilometers. It was built during the failed conversion process in the 1970s, and because of its proximity to Mexico, the signage was never converted back to miles. I believe it’s the only U.S. highway signed in kilometers.
Stephen Downes pretty much hit the nail on the head as far as the Canadian experience goes. As Canadians, we seem to have adopted a system that uses the ‘best’ of both the Metric and Imperial systems. And that’s not limited to just the folks that grew up using both.
When I ask my 8 year old granddaughters how tall they are, they will always answer with feet and inches and when if I ask them how much they weigh, they will always answer in pounds. And these are kids that have known nothing but the metric system in their brief school careers.
And, as a farmer, I harvest my crops in bushels but have no trouble selling them in tonnes.
In the UK the situation is complex. Metric measures are seen outside of the classroom, but my generation and my parent’s generation still think in Imperial measures.
I was taught Imperial measures as a child, coped with decimalisation as a young adult, and now in middle age drift back and fore between the two.
As a teacher I worked exclusively in metrics while frantically trying to convert in my head. In my experience working in metric measures is so much easier than imperial, all maths education should be done in base ten. Period.
Here in Europe, the EU had legislation relating to full metrication for member countries.
But now they’ve changed the rules as this news item shows.
http://news.bbc.co.uk/1/hi/uk/6988521.stm
We want to GO Metric NOW. WE want to remove the old US customary measuring system and WE WILL DO IT.
http://www.metrication.us
I have had pretty much Stephen Downes experience being taught in metric measure and knowing my height and weight in feet and pounds respectively. I’m working on improving this for my own kids using centimeters and kilograms for their heights and weights but I still find it a bit difficult despite the fact that I know that a finger width is approximately 1 cm (a little big but great for grade schoolers), from my shoulder to the tips of my fingers on the other side is a meter (elbow out to fingers on the other side for my students) and my hand is approximately 10 centimeters or a decimeter wide. I have a cook book that gives all the measures for store purchases in metric but the measurements for cooking in cups and teaspoons, etc. It’s a Canadian book and reflects the mixed Canadian food measures. It is wonderful for students in upper level maths and sciences to have their grounding in the system that is standard in the scientific community.
Now if you guys did go metric maybe that would trickle down over here for dimensional lumber etc. Although similarly to Stephen, inches or centimeters – makes no difference to me.
This has been really interesting, hearing how people outside the US have adapted. I assumed that “going metric” meant just that, but those of you who’ve been converted describe hybrid situations. Culture plays a bigger role than I realized, and illustrates the difficulty of systemic change.
My first practical use of metric was in the US Army when I was based in Germany. We had to know km for map-reading and land navigation, electronic warfare, etc. I’ll leave the ironic implications for the reader.
I felt like an idiot during my years in Europe, and still do here in Asia when I have to buy gasoline, shoes, clothes, and when asked my weight and height. I get the “dumbass” look when I say “5 foot 10″ or 170 pounds. You’d think our government would want to spare us the honor of embarrassing our national reputation. Wait…no you wouldn’t.
Post a Comment