A handheld counter is provided having a housing forming an opening, and inner sheath, an engagement member, and a sensor. The inner sheath is located in said opening and movable relative to the housing. The inner sheath forms a cylindrical cavity for receiving a writing instrument. The engagement member is connected with the inner sheath and frictionally engages said writing instrument upon insertion of said writing instrument into said cavity. The sensor is positioned to detect movement of said inner sheath and generate a signal in response to movement of said inner sheath.