Hello JRood,
In order to get the Sum of all the values in a single column, Please follow the steps mentioned below:
Step 1 : Load the desired Dataset

Step 2: Compute a new column with any value - (In this case "Random") and create a lens of this view.

Step 3: Use the group by function, to group by column test and perform the aggregate function on Column A to get the sum of all values in Column A

Step 4: Perform a lookup to the "Look up View" created in Step 2 using the following connection options


Step 5: Remove the undesired columns.

I hope this helps!
Thank You,
Akshay