[. . . ] In order to get the most out of your new calculator, read this instruction manual carefully and keep it in a safe place for future reference. [. . . ] Application of liquid (Please refer to image A) Remove the protective cap located at the top of the calculator, and apply the liquid into each liquid cell with the liquid applicator provided. Fill up the cells up to about 3/4 of their capacity, then place the cap back in position. Water as a power source If you use water as a power source, add some table salt into it before applying it into the liquid cells. Before you start, use water as a power source and add table salt to it (1 teaspoon of salt for 1 cup of water). Power source renewal When the calculator's energy becomes weak, please renew its power source. Under normal use, your calculator operates for one month after a new replenishment. Note: you can install 1 X AG10 battery (not included) in the battery compartment located at the back of the unit. For any claim under the warranty or after sales service, please contact your distributor and present a valid proof of purchase. [. . . ] Please actively support the conservation of resources and help protect the environment by returning this appliance to a collection centre (if available). [. . . ]