+394 A certain Greek mathematician was born in 430 B.C. His father was born 55 years earlier. Find the year in which his father was born.
In what year was his father born? _____ B.C.
+633 BC can be counted as "negative" years, so going back in time makes them increase. That means the man's father was born in 485 BC.
+633 BC can be counted as "negative" years, so going back in time makes them increase. That means the man's father was born in 485 BC.
