Metric is so simple. Everything is in 10ths. 10 mm = 1 cm, 100 cm = 1 m (little over 1 yard), 1,000 m = 1 kilometer (about 1/2 mile). 1 cubic cm = 1 gram. 100 grams = 1 kilogram or 1 liter (little over a quart). 1,000 liters = 1 metric ton (little over an English ton). 1 bar = 1 atmospheric pressure which is 14.7 lbs/sq inch. (They measure atmospheric pressure in milibars). Speed is kilometers/hour.
Then you have tools measured in mm's. Each number up is a larger tool. So simple. 5mm wrench is smaller than a 6mm wrench. Easy. No 1/4's, 1/8's, 5/16th.s stuff.
We voted in the early 1900's to go to the metric system. One vote shy in the senate and we stayed with the English system. English was chosen over Metric in the early 1800's because we traded more with England and her colonies world wide than anywhere else. Napoleon had the metric system devised on 10'th to keep it simple, because he conquered Europe and every country had their own weights and measures and he wanted every thing standardized. Thus the world went with metric. Numbers are universal in every country. Metric is universal also. If China prints the weight or measurement in metric it can be read by everyone in the world. Only their language can't.
I think we eventually will go to metric. It makes sense. The medical, scientific, NASA, and many others also use metric. Oh, Water freezes at 0 C. It boils at 100 C. However, many scientists use the Kelvin temperature scale. Absolute zero is 0, which is -several hundred degrees F, because deep space far away from the sun is absolute zero.
