I use $CIRCLE_BUILD_NUM in different jobs in a workflow (but it seems like that get incremented in between jobs of the same workflow)?

I did some research and it looks like I can switch to CIRCLE_WORKFLOW_ID which is unique for the workflow but then the ID is some really long string, not like the build num which is a small integer, nice that I can use to append to build numbers and docker tags and such.

Any ideas?