I recently wrote about Panama’s slightly schizophrenic association with weights and measures https://onemoregoodadventure.com/2012/05/06/how-metric-system-may-save-teen-live
Mileages and speed limits are measured in kilometers rather than miles. Land is measured in meters and hectares instead of yards and acres. On the other hand while liquids, like soft drinks and beer are labelled in milliliters milk is still sold by the quart and gas at the pump is measured in gallons, not liters. Meat, vegetables and bread are sold in pound and ounce portions, not grams and kilograms.
These last vestiges of American imperial hegemony (Panama is, after all, a creation of the United States) are being stripped away. No later than December 12th, by Law 52 of 2007, pounds and ounces will officially be replaced by kilograms and grams and ounces, quarts and gallons will become liters. We’ll see how easily Panamanians adapt to asking the butcher for “quinientos gramas de carne molida,” instead of the”libra” of hamburger they grew up with.
One More Good Adventure 
It will be painful for me to adapt to these new measurements. Will have to carry a small calculator to make the conversions on the spot. Afterwards it will be business as usual.
Omar.-
I don’t know, amigo. Despite three years in France and Spain I never did get the metric thing down pat. I worked with the theory “close enough for government work” in figuring things out. We know that a kilogram (1,000 grams) is 2.2 pounds. So close enough is quinientos gramos (500 grams) to a pound works for me. A liter of gasoline (1,000 ml) is roughly a quart, so four liters of gas is a bit more than a gallon. I also never got the centigrade thermometer thing down, but I do know the formula by heart, though. Centigrade degrees X 9 / 5 + 32 gives me REAL degrees.
I don’t think it will be a big problem. My experience is once you use it for familiar things it evolves VERY fast becoming a reflection. Otherwise I would go crazy when traveling!