Cellprofiler math module

Need some help with the math module:

  1. How does it determine what objects are used in division?
  2. Is there a way to make sure certain objects are used?
    The overarching problem is that I need to ensure that vacuole measurements are divided by the cell measurements of the cell that they are in. I thought that relate objects would accomplish this, but that does not appear to be the case. Here’s an example:
    So, vacuole 4 has a parent of cell 5, so the intensity of vacuole 4 needs to be divided by the intensity of cell 5. This is not the case, vacuole 4 intensity is divided by cell 4 intensity.
    Here’s an image showing the intensities that need to be divided: