Simplify the following text for a Grade 5 native English-speaking person.
Original: Vinculum is Latin for `` bond '' , `` fetter '' , `` chain '' , or `` tie '' , which is roughly suggestive of some of the uses of the symbol . The vinculum was developed in the 12th century by the Moroccan mathematician Abu Bakr al-Hassar .
Simplified: ( Vinculum is Latin for `` chain '' . )