I've run into a situation where I wonder if we have been brailling it correctly. In Nemeth Rule V §32d it is stated "When a type-form indicator is used with numerals only, it is effective until terminated by a space, a numeric indicator, or any non-numeric symbol.”
This is where my quandary lies. Does an operation sign qualify as a non-numeric symbol?
Here is an example from one of my books: 3●3●2 = 18
Here are the two ways we see to braille it: .#3*.#3*#2 .k #18 or .#3*3*#2 .k #18
Now if the rule is interpreted as the operation sign being a non-numeric symbol would it be brailled as follows: .#3*.#3*2 .k #18
Please give us any guidance you feel is appropriate to understand the proper way to emphasize this example.
Rule II defines and lists numeric signs and symbols. An operation sign is not a numeric symbol. Your third transcription is correct -- each italicized numeral requires an italic indicator and a numeric indicator. The numeral 2 does not need a numeric indicator since it is unspaced from the preceding operation sign.
First, you need to determine if it is necessary to retain the boldface. Read the accompanying text -- is the non-regular type really necessary for the understanding of the problem or sample? If you decide that it is needed, then I would explain in a transcriber's note. Something like "Numerals 4 and 5/8 are printed in boldface type."