The Welch Scientific Company designed the low cost Demonstration Analog Computer #7568 as a basic introduction to the general method of operating analog computers. A portion of this analog computer is digital since the resistances used are digital. In certain cases the correct answer had to be calculated as an average of two possible answers given by the resistor dials. This computer permits setting up a number of electrical circuits, which may be used to solve several types of simple non-electrical problems. It has accuracy of about 2%. With such accuracy the purpose of the computer was not to serve as an accurate computing device, but rather as a machine for providing estimates, demonstrating computing principles and for introduction into computing.

The Demonstration Analog Computer is capable of the following calculations:
* Multiplication
* Division
* Roots
* Powers
* Calculation of a compound interest
* Trigonometric formulas