If ten men wish to make a Minyan in a room with a curtain that separates the room into two sections, must they all be together on one side of the curtain, or are they considered a Minyan even if some are on one side and some on the other? The Halacha in this case depends on the purpose of the curtain. If the curtain was hung for privacy purposes, so that people on one side would not see the people on the other, then we can disregard the curtain with respect to the formation of a Minyan. Such a curtain does not constitute a Halachic separation, and thus the men on the two different sides combine to form a Minyan. If, however, the curtain was hung for a halachic purpose, to separate the room into two distinct halachic areas, then these areas are treated as separate rooms with regard to the formation of a Minyan. An example would be a room with a Sefer Torah, where a curtain was hung to allow on the other side of the curtain activities which are not allowed in the presence of a Sefer Torah. Since the curtain was placed for the purpose of making a halachic partition, then the room is considered halachically divided, and thus ten men who wish to form a Minyan must assemble on one side of the curtain. (However, once ten men assemble on one side, those standing on the other side are considered participants in the Minyan.) Importantly, this Halacha applies only if the curtain reaches the ceiling. If it ends more than three Tefahim (handbreadths) from the ceiling, then it does not qualify as a separation, even if it was hung for halachic purposes. Additionally, this discussion pertains only to a cloth partition. If the partition is a solid wall, made from wood or some other firm material, then it constitutes a halachic partition regardless of the purpose for which it was placed, and therefore the ten men must assemble on one side of the partition. Summary: A curtain that reaches the ceiling is considered a halachic partition that divides a room into two separate rooms if it was hung for a halachic purpose, such as to make a separation from a Sefer Torah, allowing on the other side of the curtain activities which are forbidden in front of a Sefer Torah. In such a case, ten men who wish to form a Minyan in the room must gather on one side of the curtain. If the curtain does not extend to within three Tefahim (handbreadths) of the ceiling, or if it was hung for some other purpose, then men on both sides of the curtain can combine to form a Minyan. A solid partition divides the room regardless of its purpose, and thus the ten men must assemble on the same side of the partition.