1, Faster calculate than commen calculator (No need operate + - 0 +/- = and decimal. When you account).
2, LCD display double lines (11 digit*2 line =22 digits).
3, Auto Replay the calculation step by step, as check the input digits wrong or not.
4, Double storage.
5, Mixed arithmetic of add(+), minus(-), multiply(*), dividing(/). Eg: (110+220) multiply (330+440-550) dividing (660-770+880).
6, Input digits from left or right.
7, Color: Dark-green/silver/black/blue.
8, Battery: 550Ma, solar battery optional.