I think Nat hit a bullseye. To the U.S. way of thinking, a centimeter behaves like an inch, i.e., it is a larger unit that seemingly gets divided up. Working with millimeters is actually easy, but some people might think it is difficult because they can't go dividing millimeters fractionally. There is nothing to divide. Working with millimeters is more algebraic. All you have are integers. With centimeters, one might try looking for quarters and eighths lines even though they are not there, but the terrain is more familiar. ----- Original Message ----- From: Nat Hager III To: U.S. Metric Association Sent: 07 Feb 13,Tuesday 10:44 Subject: [USMA:37944] RE: Metric at the hardware store
So the question I have is this. How did the centimeter become so dominant in American metrication? I think it's more compatible with "inch-type thinking", since the basic unit is some fraction of an inch and it still allows you to think in terms of "one" of something. Millimeters is a more radical departure, where the basic unit is 100 mm and you think of either "percentages" of 100 mm or "modules" of 100 mm stacked together. Little more of a learning curve, but far easier when you get used to it. My usual class handout attached. Nat
