Apr 03, 2015 · This metric is a measurement of your profits relative to your costs. In theory, ROI is pretty simple to calculate (at least for ecommerce websites). Subtract the cost of your goods from your revenue and divide that by the cost of the goods. In the metric system of measurement, designations of multiples and subdivisions of any unit may be arrived at by combining with the name of the unit the prefixes deka, hecto, and kilo meaning, respectively, 10, 100, and 1 000, and deci, centi, and milli, meaning, respectively, one-tenth, one-hundredth, and one- thousandth. Apr 20, 2011 · The SI system (based on metric measures) beats the imperial system hands down on items 2 and 3, and because of this now has a large advantage also on item 4. Item 2: In Imperial you might measure (heat) energy in BTU and mechanical energy in some mixture of foot-pounds-seconds, but then you need a conversion factor to compare the two. Metric Units The units of measure developed in Europe and used in most of the world. Like the decimal system, the metric system uses the base 10. Metric units for length are millimeters, centimeters, meters, kilometers. Metric units for weight are milligrams, grams, and kilograms.