Yes, there is. In the survey flow, after the block that contains the question add this:
Set Embedded Data: numSelected = ${q://QIDxx/SelectedChoicesCount}
Replace QIDxx with the actual QID.
Unfortunately, it is one of those cases where Qualtrics doesn't make it available in the Pipe Text Menu (Please vote for Product Idea Include All Possible Piped Field In Piped Text Menus).

Hi Tom
Thanks for the solution, will this work post interview completion? It's a question my client has asked now that the fieldwork has almost finished!
Arthur

https://community.qualtrics.com/XMcommunity/discussion/comment/51032#Comment_51032No, unfortunately not.

@TomG I have followed your selectedchoicescount posts and have tried to use it in my survey as well, but am getting no data from a martices. See the attached embedded data block that follows the question block in the survey flow. Any guidance would be appreciated. As a side note, the matrices has 5 scale points, not sure where the error is located or if I would be better off to figure out the JS solution.

My previous answer was for a multiple choice question.  For counts of matrix scale points use:

${q://QIDxx/SelectedAnswerCount/1}