I have to say that I use a lot of metric units with my children. My
children know that their school is 1000 meters away from our home via
the roads, or 1 km or 10 dekameters (dam), etc...
We bike in km/h and measure the distance in km. We even mark the trails
in km with a small stripe of paint. Our GPS is set to SI units. My car
speedometer lists km. Our weather instruments measure mm hg for air
pressure. All of my maintenance records are recorded in Metric.
Mapquest directions I download are in metric units and printed on A4 paper.
At home I am conducting a science experiment with my child for a school
project. She has been keeping all data in metric units. Even the paper
we use is A4. You can bet that the poster board will be A1 or A0. Even
the computer we use is set to SI.
On the weight and height subject: My younger child was born and I saw
that the measuring devices were metric. They were about to calculate,
when I asked them to record the birth weight and height in g and mm.
They did with a conversion next to it. I was pretty surprised in there
willingness.
I was a product of the first teachings of Metric in the US in 1976. I
never thought it was hard to use, and I have used the system ever since
(sometimes frustrating my parents). I still have my metric only ruler
from that time frame.
Even at the office I use metric whenever I can. My industry has a lag in
this area. I deal in printed matter, and the measurement system for
paper is truly bizzare. Paper is measured in a basis weight with a
certain number of sheets for a specific size of paper. What a mess. It
is so easy to calculate paper use based on grams per square meter. I can
perform a calculation in my head that takes others a very long time. It
is nice to know that we printed a lot of A4 manuals in Wisconsin.
Some day I hope we come to our senses and accept what is a standard
everywhere else.