In Canada we use the metric system just like in Britain but we only started in the early 1970s. So our cars drive 100kilometers/hour, we love it when its 32 degrees celcius, and we weigh in grams and kilograms.
There are still some Canadians that use the older Imperial method and many people use a combination of both. For example, I think of cold temperatures better in Celsius (I understand -10 degrees C better than I understand 20 degrees F) but for hot temperatures I am better in Farenheit (90 degrees F means more than 30 degrees C). I weigh myself in pounds but I understand distance best in metres and kilometres. Its twisted and confusing. The next generation will have been in Metric their whole lives so they will only think that way.
We still use teaspoons and tablespoons for measurements in cooking as well. There are 3 teaspoons for every tablespoon. 1 Teaspoon is 5 millilitres.
For kids - metric is great as most things are based on 100. 100 centimetres to 1 metre (vs having to remember 12 inches in a foot or 39 inches in a yard).
Great web site for conversion is:
http://www.onlineconversion.com/
Math Lesson 101 is over for the day.