In U.S. currency, one million pennies are worth 10,000 dollars. A penny is worth one cent, and one cent is 1/100 of a dollar. In other words, a dollar is equal to 100 pennies, so one million pennies divided by 100 provides the worth in dollars.
Minted pennies prior to 1982 were composed of mostly copper. However, due to rising metal prices, pennies now only contain about 2.5 percent copper. In fact, it costs about 1.8 cents to produce one penny. Currency values differ from country to country, so a penny in the United States is not worth the same amount as a penny in another country.