hp 35s - Entering and Evaluating Equations

The HP35S can be used for specifying an equation to evaluate. Suppose there is a frequent need to determine the volume of a straight pipe. The equation is

V = .25 pi d2 l

Where d is the inside diameter of the pipe, and l is its length. The calculation could be keyed in over and over.

For example:

.25 {ENTER} {RightShift} {pi} {x} 2.5 {x2} {x} 16 {x} calculates the volume of 16 inches of a 2 1/2-inch diameter pipe (78.5398 cubic inches). However, by storing the equation, the calculator can ‘remember’ the relationship between diameter, length, and volume - so it can be used many times.

Put the calculator in equation mode and type in the equation using the following keystrokes:

By comparing the checksum and length of the equation with those in the example, it can be verified that the equation has been entered properly.

Evaluate the equation (to calculate V):

These procedures are also applicable for HP 33s.