The left (English) ... mass pieces ... are 1 lb, 8 oz, 4 oz, 2 oz, 1 oz, 1/2 oz, 1/4
oz. ... the metric (mass pieces) (are) 500 g, 2 x 200 g, 100 g, 50 g, 2 x 20g, 10 g, 5 g).
... here is a
case where colloquial is better: the factors-of-2 progression ... makes using the colloquial
weights easier and faster to use, plus only 7 weights to 9 weights for
approximately the same mass range.
I don't see how the the colloquial set of masses is "easier and faster" to use. Yes, it is easier if you restrict yourself to the halves, quarters and eighths, etc. used predominently in Ye Olde English system. But suppose you need 1.3 lbs? How would you do it? I don't know. In metric, the nearest round equivalent is 0.6 kg which is easily measured out using the 500 g and the 100 g mass. Score 1 point for metric.
OK, so that problem clearly was designed to be favorable to metric (by using a decimal fraction). But now let's take an example that is designed to be favorable to English units.
How about 3/4 lb, and the nearest round metric equivalent which would be 350 g. Yes, in this case the English masses are easy; just use the 8 oz and the 4 oz. But the metric is easy, too; use 200, 100 and 50 g masses. It's a tie.
Net result: metric still wins.
I understand that the pure powers of 2 used in Ye Olde English system require one or two fewer masses (depending on the range to be covered) but that's not much of an advantage. And there actually are the same number of DIFFERENT masses needed in the metric set, you just need an extra 20 g and an extra 200 g, two of each instead of only one. That's a small price to pay for the advantages of a purely decimal system.
Regards, Bill Hooper Fernandina Beach, Florida, USA
