[. . . ] Calculations using memory Before saving a new value to the memory, the content must first be deleted by pressing the 'MRC' key twice and then pressing the 'AC' key to delete all previous calculations. To add a value to the memory, enter the chosen number or calculation and then press the 'M+' key. To deduct a value from the memory, enter the chosen number or calculation, and then press the "M-" key. [. . . ] The round down/up selector allows you to choose to round down to the nearest lower unit (position " "), round up to the nearest higher unit (position " "), or a result automatically rounded up/down (position "5/4"). To correct a number, press the " " key until you reach the number you want to enter. To completely delete a number you have just entered, press "C/CE" once. M+/M-/MRC - Memory operation keys +TAX/-TAX/RATE - these keys are used to perform operations using a tax rate set by the user. Then, press the "RATE" key, followed by "+TAX" to confirm. Before using this calculator for the first time, remove the static label from the LCD screen. In order to delete the error message and any other calculations, press "AC". To replace the battery, open the battery compartment at the back of the unit using a coin. Automatic switch off: If no key is pressed, the calculator will switch itself off automatically after approximately 6 minutes. Abnormal Conditions If this calculator is exposed to a powerful external electric field or shock during use, an abnormal condition may occur in which all the keys, including AC, do not function. Note that the memory contents will be completely cleared when this operation is performed. Press the RESET switch only in the following cases: After replacing the batteries. Handling precautions Your calculator contains precision components, never attempt to take it apart. - Take care not to drop your calculator or allow it to receive any other impacts. - Do not leave your equipment in areas exposed to dampness, dirt, dust or high temperatures. - Make sure your calculator does not come in contact with water or with any other liquid substance; this could produce a short circuit or a potential risk of fire. [. . . ] Note: It is recommended that all packaging be kept for future reference. Keep this instruction manual in a safe place as it contains important information. In our constant concern for improvement, the colours and details of the product may differ slightly from those shown on the packaging. [. . . ]