Change is the money a customer receives back when they have made a purchase.
Often the customer gives the merchant more money than the amount due because the
customer may not have the exact coins and bills that are needed. The merchant
determines how much extra was paid and returns the excess which is called change.
How to find the least number of coins to give in change:
 Determine the total amount of change due.
 Start with the highest denomination of coins or bills
 Use as many of this coin as possible without exceeding the amount of change due
 Repeat this process with the next lowest denomination of coin or bill
Example of making change for purchase of $2.11 and customer paying with a $20.00 bill
 Determine change due  $20.00  $2.11 = $17.89
 Get one $10 bill but two would be too much  have $10.00 for change
 Get one $5 bill but two would be too much  have $15.00 for change
 Get two $1 bills but three would be too much  have $17.00 for change
 Get 3 quarters but four would be too much  have $17.75 for change
 Get 1 dime but two would be too much  have $17.85 for change
 Get 0 nickels  even one would be too much  have $17.85 for change
 Get 4 pennies  5 would be too many  have $17.89 for change

  NOW COUNT THE CHANGE OUT TO THE CUSTOMER 

 Say the original amount before giving any change
 Count the change from the lowest denomination to the highest denomination
 The final count should be the same as the amount the customer gave you
 You should say: "Two eleven"  before starting to give change back
 "two twelve, two thirteen, two fourteen, two fifteen"  as the pennies are given
 "two twentyfive"  as the dime is given
 "two fifty, two seventyfive, three dollars"  as the quarters are given
 "four dollars, five dollars"  as the one dollar bills are given
 "ten dollars"  as the five dollar bill is given
 "And twenty dollars"  as the ten dollar bill is given
This process accomplishes the following:
 The customer has the least possible coins in their purse or pocket.
 The amount of money returned is double checked, when it is gathered and when given to customer.
 The amount of change due is double checked by counting change.
 The possibility of a misunderstanding is eliminated.
 The merchant and the customer are both treated fairly by making sure the change is exact.