There is a history function. The input value plus tax, you can switch in the tax. *Function -arithmetic -character Back button -input clear button -± swap reversal button -history display -setting of rounding (truncated, rounded, rounded up) -the character size change -change of tap sound -change of vibration at the time of tap *How to use 1. Enter like a normal calculator. 2. If you press the [=] button it will be recorded in the history. 3. You can change various settings in the [MENU] butto