Best Calculator CT- 712 which is exclusively designed with special features to meet the needs of young students, Businessmen and professionals. Automatic Power Off key When there is no need of calculator longer time, calculator gets switched off by key 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 Hyper Solar Power This calculator is dual powered with a high power solar and back-up battery to ensure continuous and long-lasting usage. Big Display , Check & Correct, Automatic replay, 112 Steps Check, two way power ( Solar + Battery).