>I agree. I really regret the day we went "metric". I think the idea of twelve pence to a shilling, threepenny bits half crowns etc helped give people a wider perspective on maths than 10 10 100 1000 etc.

To some, who were inclined to think about it, perhaps. For most, it scared them away from maths altogether. They learned what they had to, by rote, without much thinking. I've seen a lot of those in the US - a clerk cutting cloth was completely unable to convert 2/3 into decimals, but she had a large cheat sheet taped to the desk, and was equally unable to find 2/3 on it, because the various fractions were listed by size, not alphabetically. It took her considerable time to find that it was .667 (as per rounding rules set by Walmart), and she was so happy to have mastered the art of finding it on the sheet that she forgot to type the integer part, so instead of 2.667 we were charged for only 0.667 yards.

Or the old case when I was buying tobacco from the American American's shop (Smokin' Joe's), where they felt no compulsion to use imperial measures, so the bag contained 200g. Another customer asked me how many cigarettes do I get from a bag. "Well, normally one cigarette holds one gram, this is 200g, so that's 200 cigarettes". "Wow, how did you calculate it so fast? I never got around to understand those metrics".