The Slide Rule is a mechanichal analog computer,slide rulers are closely related to nonagrams. The slide rule is used primarily for multiplication and division, and also for functions such as exponents, roots, logarithms, and trigonometry, but typically not for addition or subtraction. Though similar in name and appearance to a standard ruler, the slide rule is not meant to be used for measuring length or drawing straight lines.

The Slide Rule impacted the design of structures like bridges and buildings. The slide rules predecessor is Pascal's calculator