The calculator is a small but indispensable item for any home or office. Basic display calculators can be purchased for as little as $2 to $10; they are usually solar- and/or batter-powered.
Printing calculators are available from $10 to $20. Financial calculators are useful for those in certain industries; they typically retail for between $10 and $35, depending on the calculator's manufacturer and features. Graphing calculators, because of their large screens and advanced functions, retail for between $40 and $200.
A surprising number of people forget that their computers also have a calculator application, usually with basic and advanced functionality. External number keypads are especially handy for laptop users, who would ordinarily use the cramped row of numbers on the laptop's keyboard. These can generally be purchased for between $15 and $50, with some models acting as a USB hub as well.
