The system of measurement has no effect on fractions, so that:
two-thirds of a metre is two-thirds of a metre, just as two-thirds of a mile is two-thirds of a mile.
two-thirds of a second is two-thirds of a second etc.
In SI units, that would be the Newton.In SI units, that would be the Newton.In SI units, that would be the Newton.In SI units, that would be the Newton.
Derived SI units.
Base units
SI units: kilogram, gram English units: pound-mass, slug
It is the International Standard of units.
In SI units, that would be the Newton.In SI units, that would be the Newton.In SI units, that would be the Newton.In SI units, that would be the Newton.
66.666%.
Derived SI units.
SI and metric are the same units.
International System of Units (SI)
Base units
most of the world does SI so more people can understand with it in SI units
most of the world does SI so more people can understand with it in SI units
SI units are more accurate than English system units
The SI has 7 base units. These units can be combined in an almost unlimited way to form other (derived) units. The Wikipedia article on "SI derived units" lists some examples.
Si and metric are the same thing. SI was a redefinition of metric in 1960.
8.