We moved from the US (that still doesn’t use metric) to a Caribbean country and now my 11 year old daughter has homework I don’t understand. She has to figure this out:
4 kg 3 hg 5 dag x 4
Most of these she does well, but we don’t know what “dag” is. Anybody else?
dag = dekagram = 10 grams
GTPhD1996
Looks like 10 grams, or a dekagram.
Doh!
4 kg 3 hg 5 dag x 4
4 kg = 4000 g
3 hg = 300 g
5 dag= 50 g
x 4 = 17,400 g.
17400 gr divided by 1000 = 17.4 kg
or 17 kg, 4 hg.
Right?
(Thank god I didn’t grow up in a country with a “Common Entrance Exam”)
Are you sure you’re not leaving out some addition signs or paretheses there?
I know what the da and d prefices mean, and I use them when I want to be ostentatious, but do people in metric countries ever actually use them as a matter of course?
Er, on second thought, I see what the deal is. Nevermind. I’ve been thinking like a scientist for too long. Yes, 17.4 kg is right.
Nah. We just say ‘This package contains 3.5 kilograms’ or ‘Next exit 500 metres’ or whatever, generally keeping to the ‘power-of-3’ multples. The only common exception around here is the centimetre. I remember how surprised I was to run across some European stuff mentioning hectolitres and centilitres… we just don’t use them in common discourse.
I’ve never heard anyone say ‘3 kilograms, 5 hectograms, 4 dekagrams, 2 grams’ as a way of naming one measurement. It looks like a way to artificially exercise the knowledge of the intermediate multiples…
I would have taken a shorter approach:
4 kg 3 hg 5 dag x 4 =
4.35 kg x 4 =
17.4 kg
I grew up in a Metric country (Japan) and was introduced to the dl (deci-litre) in elementary school. I think it was a misguided effort by textbook publishers to allow use of nice numbers (integers or fractions of order 1) in classroom demonstrations.@ I haven’t seen it since then, and I’ve never seen any other use of da or d prefices.
Almost all measurements are done by power of 1000 steps, as in science. The obvious exception is cm, of course. Also the hecto prefix is used for hectare (100 ares, 1 are=100 square meters), and the Japanese weather bureau uses hPa (hecto-Pascal) for atmospheric pressure. (They used to use millibar and wanted to keep the numbers the same.)
I do remember now, when I was in Italy, seeing cans of soda labelled “33 cl” for 33 centiliters. That wasn’t too hard to figure out, either.