Editing Gradian (section)

== Relation to the SI system of units {{anchor|SI}} ==
The gradian is ''not'' part of the [[International System of Units]] (SI). The EU directive on the units of measurement<ref name="EU units"/>{{rp|9–10}} notes that the gradian "does not appear in the lists drawn up by the [[General Conference on Weights and Measures|CGPM]], [[General Conference on Weights and Measures#CIPM|CIPM]] or [[International Bureau of Weights and Measures|BIPM]]." The most recent, 9th edition of the [[International System of Units#SI Brochure|SI Brochure]] does not mention the gradian at all.<ref name="SI Brochure 9th ed">{{SIbrochure9th}}</ref> The previous edition mentioned it only in the following footnote:<ref name="SI Brochure 8th ed">{{SIbrochure8th}}</ref> {{blockquote|The gon (or grad, where grad is an alternative name for the gon) is an alternative unit of plane angle to the degree, defined as (π/200)&nbsp;rad. Thus there are 100&nbsp;gon in a right angle. The potential value of the gon in navigation is that because the distance from the pole to the equator of the Earth is approximately {{val|10000|u=km}}, 1&nbsp;km on the surface of the Earth subtends an angle of one centigon at the centre of the Earth. However the gon is rarely used.}}