I am having a hard time understanding new rules. In a topic entitled "Spatial calculations in UEB code" guidance was given for mathematics in UEB. Yet in a topic entitled "Provisional Guidance, Basic Guidance" the answer stated that any number with a + 0r - sign in front of it was to be done in Nemeth (within the code switches). Are transcribers in the United States doing both?
The decision to use UEB math or Nemeth is an agency/state decision. The first article you mentioned would only apply if your state/agency is using straight UEB to do math books. The second lets transcribers know how to use Nemeth within a UEB context (using UEB only for the literary text and using Nemeth for the math). If your state/agency is sticking with Nemeth, these guidelines should be used for the whole book. If you are using UEB math, no Nemeth symbols should be used in your book.