int dollarCount, quarterCount....
dollarCount = changeOwed / dollar;
changeOwed = changeOwed % dollar; // takes the remainder for example $4.25  would remain $0.25 which gets picked up below..
quartersCount = changeOwed / quarters;
changeOwed = changeOwed % quarters; // takes the remainder..
// repeat for dimes/nickels/pennies until it Has to be 0