Solve large problems with the ten digit input of the Texas Instruments BA-20 calculator. Powered by the solar energy, this TI basic desktop calculator is turned on simply by placing it to an adequate light source. You can easily solve cost-sell margin problems with this TI calculator. To perform repetitive calculations, the Texas Instruments BA-20 calculator offers an automatic constant feature, which allows easy calculation by just entering the new number and press the 'equal-to' key. The large keyboard of this TI basic desktop calculator enables ease of operation. You can easily calculate squares and square roots with dedicated keys of this TI calculator.