Average operating assets is the average of the assets used in an operation over a period.  Once the period begins the value of the operating assets is then called beginning assets.  Through the period assets may be added, or subtracted.  For example, if you make donuts and you buy a new creamer so that you can get more cream into one donut, the price of the creamer is added to the value of your operating assets.  On the flip side if you sell a creamer because you have too many and the proceeds from that sale do not go back into the operation, then the value of the creamer is subtracted from the value of your operating assets.  At the end of the period the operating assets are called ending assets.

The calculation for finding the average operating assets is as follows:

Average operating assets = (Beginning assets + Ending assets)/2

Knowing the value of average operating assets is valuble for computing such things as turnover and ROI.