Well,
fred, nobody said anything about this calculation being done in one�s head. In fact, if
lizzyminto (who posed the question) needs to ask how to perform the calculation, I would not in my wildest dreams imagine (s)he is able to do the arithmetic mentally.
The details of the required calculation are unimportant. I cited it just as an example to support
geezer�s alarm at the lack of skill that seems to be endemic. Interestingly, I found another even more alarming, this time bizarrely posted under �Business & Finance�:
http://www.theanswerbank.co.uk/Business-and-Fi nance/Question710437.html
The reason we use gallons is that it is a convenient measure for bulk liquids. Few people know how many miles to the litre their car does. Manufacturers provide consumption figures as �litres consumed per 100 kilometres� � absolutely useless. This is manifestly obvious from
lizzyminto�s need to know the fuel consumption in miles per gallon. The reasons we use miles are:
- It is illegal in this country to provide roadsigns in anything else.
- Car speedometers are calibrated in miles per hour
- Speed limits are quoted in miles per hour
Some of the things you mention are symptoms of enforced metrication foisted upon an unwilling populace. Nobody wanted to buy retails goods in kilograms and grams. Nobody wanted their children to have to do so. People were perfectly content to buy fuel in gallons and continue to be happy measuring their journeys in miles and their football pitch dimensions in yards.
But I digress. Whatever calculations are necessary, people seem singularly ill-equipped to deal with them.