There is little practical purpose for exchanging 50 coins for a dollar. However, it is an entertaining math problem. Ask Dr. Math identifies two possible outcomes, one involving 40 pennies and the other involving 45 cents. The easiest method involves 45 cents.
Count 45 pennies
Count out and place away 45 cents. This action yields five coins for the remaining 55 cents.
Add a quarter
Add a quarter to the pennies to achieve the sum of $0.70. A quarter is required because five dimes only amount to $0.50.
Add dimes and nickels
Dimes and nickels make up the remaining four $0.30 coins. Given that three nickels equal $0.30, only two nickels are conceivable. Thus, two dimes and two nickels make up the remaining 50 cents for a dollar.