Convert from fanega to hundred

Unit Definition (fanega)
The Fanega is a traditional unit of land area in Spain and in some Latin American countries. The unit originated as the amount of land that could be planted with a fanega (a Spanish unit of volume) of seed. It varied considerably from one area to another. In 1801 it was standardized in Spain as the area of a square 96 varas (80.2 meters) on a side; this comes to 0.643 hectare (1.59 acres). After the introduction of the metric system it became customary to refer to an area 80 meters square as a fanega. This unit is not legal but is still used informally in some parts of Spain. The Central American manzana is a counterpart of this traditional Spanish unit.

Unit Definition (hundred)
The hundred is an old English unit of area equal to 100 hides (see above). This is roughly 12 000 acres, 5000 hectares, or 18.75 square miles. The hundred is approximately the area of a village with its associated fields, so the name "hundred" came to mean a minor division of a shire or county. This use carried over to the American colonies, where, for example, many of the early settlements in Virginia were called hundreds.