Calculator apparatus

A calculator, comprising:

• an input pad that includes a sales tax button;
• a currency pad, which includes a change due button and a number of currency keys, wherein the currency keys can be depressed in order to enter numeric values associated with currency, and wherein the change due button may be used in order to produce a resultant between data provided in the input pad and the currency pad, the currency pad including a selected one or more of the following currency denominations:
• a) $1;
• b) $5;
• c) $10;
• d) $20;
• e) $50;
• f) $100
• g) 1¢;
• h) 5¢;
• i) 10¢;
• j) 25¢;
• and
• k) 50¢.