Hi Julie!
After analyzing the materials you provided to us, we turned to BANA's "Guidance for Transcription Using the Nemeth Code within UEB Contexts" (June 2016) <http://brailleauthority.org/ueb/nemeth-guidance/Nemeth%20Guidance%20Final.pdf>.
Referencing the section of that document titled "Basic Guidance on Which to Switch," we find no mathematical expressions, fragments of such expressions, or signs of operation or comparison associated with maths in the graphic, so there is no need to switch into Nemeth braille in the graphic.
If you have other questions about the materials being transcribed please let us know!
Best wishes for a brilliant and bountiful Saturday!