I think the total does not show up in the data by default. But you should be able to go into your Survey Flow and add an embedded data field to save the total.

Thank you! So I would create an embedded data "total sum" for each constant sum question, correct?

yes, that's right! make a separate embedded data field for every constant sum question you have. and just make sure that your embedded data fields come after the block in which the relevant questions appear.
if you wanted to be able to analyze the results from that embedded data field directly in Qualtrics (e.g., in the Results tab), then you should also change the "Options" for the embedded data field to something like "Number." More info about the other options on this support site.

When I attempted this, I do not see the “Total sum” option as a value to select (like the image you’ve shared here). The question I’m trying to base the embedded data off of is a constant sum question, so I do not understand why it does not show up. 

Here is a screen shot.