Question: New User: How Do I; -1.60x10^-19 (Coulombs)

How do I display / calculate -1.60x10^-19 when calculating Coulombs? This returns a "Error, invalid power" in Maple 10 (student) and Classic Maple (student) and in the calculator (student).! Frustrating, Yes I am a student and a new user and I need the help the software promises to provide.
Please Wait...