The scales of the pocket slide rule 62/83 N with graduation length 5" (12.5 cm)

The Scales of the Slide Rule 2/83 N

How to read the scales with graduation length of 10 inches, e.g. C, D, CF, DF, CIF

How to read the scales with graduation length of 20 inches: W 1 W 1 ' W 2 W 2 '

Multiplication a · b