Desktop Type 12 digits Regular percent: Regular percentage calculations. 300 steps check: Displays up to 300 previous calculation steps. Recheck function: The recheck function allows confirmation of errors by sound when checking calculations. If the user presses an incorrect key when performing a second calculation to check calculation results, a buzzer sounds to alert the user of the error. Tax calculation: Automatic calculation of price plus tax, price less tax, discount, selling price, tax amount, discount amount, and margin amount. Solar & Battery: Solar powered when the light is sufficient, battery powered when the light is insufficient. Function command signs A symbol (+, -, ×, ÷) on the display indicates the status of operation you are currently performing."