Add the ability to do simple math with Dynamic Text

[KevinDunlop]

Please add the ability for simple math functions in dynamic text in layouts. 

For example, I have the dynamic text for sum of all values for a certain field that represents work completed.  But I know the total overall is X.  So I want to get a percent done by doing something like: SUM / X.  As far as I can tell this isn't possible right now. 

Another case would be that I want find the different between two fields' averages and show it as text like: FieldXAvg - FieldYAvg. 

Right now, for both examples, I have to manually calculate the values then hard code the values.  That kinda defeats the purpose of dynamic text.

[VanessaSimps]

Could you use Arcade and then use the expression values for the dynamic text? 

[LoganShank]

One issue I am noticing with the most recent 3.5.5 update, is that I want to do more complicated math in my layout leveraging data from multiple layers/tables. Think of this as a vlookup in excel, sum data from table A, then pull something from a completely different layer based on a lookup and use that in my equation. Unfortunately this was only possible while $datastore was still a thing. This has now been nuked for no apparent reason drastically limiting the functionality of arcade in styling content in a layout. Additionally there are no great work arounds aside from creating a stand alone layer or table, creating a script to run actual field calcs using the same arcade to populate records in that table, then linking that content back into your map series. Way more convoluted than this process needs to be when it was perfect before.

If you agree that this is a major degradation in essential ArcPro Layout functionality, consider upvoting this idea to add $datastore and $map back in. Make Dynamic text Dynamic again!
https://community.esri.com/t5/arcgis-pro-ideas/arcade-add-datastore-and-map-to-the-layout-profile/id...