Complex sentence: Mike McCallum (born December 7,1956 in Kingston, Jamaica) is a retired boxer who represented Jamaica as an amateur at the 1976 Summer Olympics in Montreal, Canada, where he was eliminated in the quarterfinals.
Split into simpler sentences: Mike McCallum (born December 7,1956 in Kingston, Jamaica) is a retired boxer from Jamaica. McCallum represented Jamaica as an amateur at the 1976 Summer Olympics in Montreal, Canada, where he was eliminated in the quarterfinals.