Canon LS 121TS, Tax FunctionKey Features :12 digit LCD screen with punctuation Stylish metallic silver body with plastic keytops Tax calculations - will add or subtract a predetermined tax rate. Ideal for G.S.T. Business calculations - will easily calculate cost, sell and margin Backspace and sign change key Memory, percentage and square root functions Battery and solar powered Size: 148 x 107.5 x 31 mm Weight: 132 g