Citizen CT-555 N Basic (12 Digit) Price: Rs. 391 Have fun while you learn mathematics with this CT-555 N Basic calculator which is exclusively designed with special features to meet the basic needs of young students and professionals. Tax Calculation Function Now, calculating tax values is made easy with the help of this Citizen calculator which is designed with a special tax calculation function. Automatic Power Off When there is no key entry for a longer time, the calculator gets switched off automatically to save the battery life. Check And Correct The check and correct function enables you to recall and edit the wrongly entered data. Square Root The Square Root function helps you to calculate the root value of a particular number that you enter. Power Source: Battery And Solar This calculator is dual powered with a high power solar and back-up battery to ensure continuous and long-lasting usage.