"Yesterday the Euro was at $1.41. Oil I think about $84 a barrel," Castro said at one point, indicating that the interview was recorded on Friday.
He also held up a copy of a book by Alan Greenspan, the former US Federal Reserve chairman, which was published this week.
When Castro did not appear on his birthday on August 13, Cuban migrants in Miami speculated that he had had a major health setback, was on his deathbed or had already died.
The Cuban president provisionally handed over control to his younger brother, Raul Castro, on July 31, 2006 after emergency intestinal surgery and has not appeared in public since then.
He has been seen in occasional photographs and videos with visiting foreign leaders and has produced a steady of columns and essays printed by state media over the past six months.
Castro's closest ally, Hugo Chavez, the Venezuelan president, said on Friday his political mentor had undergone several blood transfusions and had almost died.
He did not make clear if he was talking about a recent relapse or if he was recounting complications that Castro suffered after undergoing emergency surgery more than a year ago.
During a visit to Brazil's Amazon city of Manaus, Chavez told reporters: "Fidel is well; clearly he has not finished his recovery. He has a little problem there but he can live like this another 100 years."