Only three countries still cling to the "English" system, whereas the whole world uses metric. The SI units were established in 1960 as part of a review of the metric system used at the time; it uses metric units because it is the current version of the metric system.
The Kelvin.
3x3x3=18 The equation is length times width times height.
It is easiest to draw it using two right angled triangles.Draw a line AB that is 2 units long. From B, draw BC which is perpendicular to AB and 2 units long. Join AC. From C, draw CD which is perpendicular to AC (clockwise if BC is clockwise from AB, or anticlockwise if BC is anticlockwise) and make CD 2 uinits long. Then AD is a line segment which is sqrt(12) units long.
5 g = 5000 mg5 g = 5000 mg5 g = 5000 mg5 g = 5000 mg5 g = 5000 mg5 g = 5000 mg