Simplify the following text for a Grade 6 native English-speaking person.
Original: Barnes & Noble continued to expand throughout the 1980s , and in 1987 purchased the primarily shopping mall-based B. Dalton chain from Dayton Hudson .
Simplified: Barnes & Noble continued to expand throughout the 1980s . In 1987 it purchased the mostly shopping mall-based B. Dalton chain from Dayton Hudson .