Which sentence states a fact?

 - Our five-cent coin is called a nickel, but it is not made out of nickel.
 - In today's economy, a nickel is almost worthless.
The first sentence states a fact.
Our five-cent coin is called a nickel, but it is not made out of nickel.
It can be proved by looking up information about U.S. coins.
The second sentence states an opinion.
In today's economy, a nickel is almost worthless.
Almost worthless shows what a person believes, thinks, or feels. Another person might have a different opinion about what is worthless.