Units Was: Where is balance 276

CBFalconer

Yes, if transitioning between two systems, it can help if you don't stubbornly try to find the exact values for conversions, and make a mental note of the useful, usual level of rounding in each situation. The least-significant digits are of no use in everyday living, anyway.

For example, grams (as such) are not used for anything in day-to-day living (here in the metric world, where I am hailing from.) You might buttes the weight of a letter in tens of grams, but not down to the precision of individual grams. If you're baking a cake and weigh out a lump of butter, you're dealing with hundreds (and tens) of grams: again, the perspective of significant numbers shifts according to what you're trying to do. When dealing with grams, you'll usually be rounding to the nearest tens and hundreds of them (or kilograms, if you go above, say, 450 g), since measuring everything down to a single-gram precision would simply be useless and even downright ludicrous in most of the everyday situations.

There was recently this MSNBC article about the Mars rovers where they had helpfully provided metric measurements in parenthesis after the imperial ones:

"Opportunity broke free after making about 3 feet (93 centimeters) of inch-by-inch progress."

This sounds weird and off to a metric reader. If imperial folks can get away with a single-foot precision in that story, "93 cm" is most definitely far too precise to have any meaning. It should be rounded off to "about 1 metre", or at least "90 cm" (or if the three centimeters really bear some significance, the measurement should be expressed in feet and inches for the imperial folks as well.)

-- znark