Convert from dekare to barn

Unit Definition (dekare)
The Dekare is a metric unit of area equal to 10 ares, that is, 1000 square meters or 0.1 hectare. In English units, the dekare equals approximately 10 763.91 square feet, 1195.99 square yards, or 0.247 105 acres. Various traditional units of land area have been identified with the dekare, including the Middle Eastern dunum (see below), the Norwegian mål, the Greek stremma, and the Vietnamese cong.

Unit Definition (barn)
The Barn is a slightly humorous unit of area used in nuclear physics. When atoms are bombarded with smaller particles such as electrons, the electrons are scattered as if the nucleus of the atom was a tiny solid object. The barn is used to express the apparent cross-sectional area of this scattering object. One barn is equal to 1E-28 square meters. Using this unit, physicists can say that such and such a nucleus is "as big as a barn", or 10 barns, or whatever. The proper SI unit to use for these measurements is the square femtometer (fm²); one barn equals 100 fm².