A single procedure as a hander for multiple events
So you checked that once you change the quantity in any row of a Goods receipt document, the platform automatically recalculates the total.
You also need the Price field to behave in a similar manner. Taking a look ahead though, you will see that similar automatic calculation of Total fields might come in handy for other documents as well.
Therefore, it is better to move the calculation of totals to some universally accessible location, so that various documents with similar attributes in their tabular sections will be able to use the algorithm.
The Common module configuration objects serve for defining these universally accessible locations. You can add them in the Common / Common modules branch of the configuration object tree. The procedures and functions stored in these modules are accessible from all the configuration objects.
So you will create a common module and move the total calculation procedure to this module. And in the document you will simply call that procedure from the common module.