Casio 14-Digit DJ-240D Basic Calculator, Black/Beige

300 steps check Displays up to 300 previous calculation steps. Recheck function with Sound Assist The Recheck function with Sound Assist 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. Localized number display Displays numbers in three digit separator formats (Standard, European, and Indian). Extra Large display Larger display makes more data easier to read. Two-way power (Solar + Battery) Solar powered when light is sufficient, battery powered when light is insufficient. Key rollover Key operations are stored in a buffer, so nothing is lost even during high-speed input. Plastic keys Designed and engineered for easy operation.