In the United States, pennies are customarily stored in "rolls" of 50. A roll is really a stack of fifty pennies that's held together by a tough paper wrapper. When you get coins from a bank, it gives them to you in rolls. Since each roll has been pre-counted, it's easy to count them out. $10 worth of pennies is 20 rolls.
"Unrolled" means loose change. My wife collects loose change in a glass jar. She takes the unrolled coins to the bank. The bank dumps them into a coin-counting machine and credits the total to her account.
You can buy coin wrappers in office supply stores and roll your own coins. The wrappers are carefully designed to hold an exact number of coins, and don't look or fit right if you try to roll, say, 49 pennies instead of 50. In the old days you'd roll your coins before bringing them to the bank, and they wouldn't bother to count them--they'd trust that your roll of 50 really contained 50. Now, they just break the rolls and toss the coins into the coin-counting machine.