Printing calculators, also called adding machines, are desktop calculators often used in the financial sector. Much larger than standard and pocket calculators, the buttons are easier to use, greatly increasing speed for financial calculations. The viewing display is also larger for more efficient readings. Normally found on desktops, printing calculators are AC power-based instead of battery-powered. The cost savings from not replacing batteries is offset as the printing function is reliant on replacement of the ink and paper supplies. However, the printer capability can be turned off on these calculators to prevent unnecessary waste.
The computing power of these devices is fairly limited to standard arithmetic, though some will offer advanced features, such as memory recall and programmable Tax keys. Print speed, noise level and multiple ink colors are additional features that higher-end models offer. The addition of the printing function gives users the ability to review their entered calculations and verify them. These print outs can then be removed from the calculator and stored with documents as proof of accuracy.