At the Whitman Coin Expo on March 28, Coin World went inside the grading room to learn about coin grading from a top grader at Numismatic Guaranty Corp. Students in the Introduction to Grading class reviewed dozens of coins and even a few counterfeits, to mimic the challenge faced every day by professional graders.

More from CoinWorld.com:

San Francisco moving on from group's plan to renovate Old Mint

1792 Birch cent brings $1,175,000 at Stack's Bowers' March 26 Kendall Foundation auction in Baltimore

Inexpensive modern United States coins makes hobby affordable

Federal investigators uncover scheme to defraud U.S. Mint with counterfeit mutilated coins

Fred Weinberg makes a living off of other people's mistakes

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