Casio sl320ter 12 digit pocket calculator casio sl320ter p this pocket calculator from casio is a must have item for any mathematics enthusiast as it features a 12 digit extra big display two way power and key rollover but that s not all as the calculator boasts a host of excellent functions br br euro conversion br percentage calculation br tax calculation br key for changing plus minus sign br 3 digit comma markers br independent memory br double zero key p casio sl320ter 12 dig