Incrementing a Sharepoint List by Value in Another SP List

[WO1]

All,

Is it possible to increment a row/column in Sharepoint List based on a value that is added into a different share point list? For example, I enter a row of "add 50" to one sharepoint list and it updates the total in the second list. I could also need to decrement as well if its "subtract 50". 

Does anyone have knowledge of any documentation or examples on how to do this (Specifically the increment / decrement from another table)? I can do the flow logic for Add / Remove, just not the increment  / decrement by firing the "upon new item added to list" criteria.

[Hardesh15]

@WO1 

So you want to use add/Sub functionality while modifying list. Then use trigger ' When new list item is created or Modified'.

You can use steps from my post for this trigger because update action makes infinite loop for flow.

https://powerusers.microsoft.com/t5/Building-Flows/Looking-for-modified-data-and-then-sending-an-ema...

Thanks

Hardesh