metric conversion

[JillGat]

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?

[GTPhD1996]

Originally posted by JillGat
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

[Berkut]

Looks like 10 grams, or a dekagram.

http://ts.nist.gov/ts/htdocs/230/235/appxc/appxc.htm

[Berkut]

Doh!

[JillGat]

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")

[Achernar]

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?

[Achernar]

Originally posted by Achernar
Are you sure you're not leaving out some addition signs or paretheses there?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.

[Sunspace]

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...

[brianmelendez]

I would have taken a shorter approach:

4 kg 3 hg 5 dag x 4 =

4.35 kg x 4 =

17.4 kg

[scr4]

Originally posted by Achernar
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?
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.)

[Achernar]

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.