Patent ID: 7033102

Claim:
A writing instrument for performing at least one non-linear calculation comprising: an elongated housing having a first end and a second end; said first end including a means for writing comprising of an ink or other writing tip, with said writing tip extending through an axial orifice in the first end; said second end having an outer surface rotatably engaged to a rotatable dial having a first numerical values scale with designations printed so as to be visible at the circumference of the writing instrument; said second end further including a second numerical values scale printed longitudinally along its outer surface and an elongated transparent window that extends longitudinally along said outer surface in parallel to said second scale; said rotatable dial rigidly affixed to a rotatable cylinder disposed radially inward of the housing within said second end and having resultant calculation values of a desired non-linear calculation printed on the outer circumference of said cylinder; and said transparent window having a sliding member including a transparent viewing area through which a resultant calculation value is viewed upon a selection of desired settings for the first and second numerical value scales.