This is the fourth part in a series of notes that will help teachers understand what SI is and how to use it in a common-sense way. This part contains information about spelling, pronouncing, and manipulating symbols.
There is no absolute agreement as to the pronunciation of the units and prefixes.
Most guides for metric practice have dropped recommendations from recent editions. On the other hand, there is a large consensus for some preferred pronunciations. In choosing a pronunciation, we suggest that one look it up in a dictionary that one considers authoritative. We provide some (possibly controversial) guidance in the tables and text, but there may be valid considerations for other choices, such as knowing the pronunciation of the name of the scientist being honored in the country where the scientist lived.
Some rules seem noncontroversial, but are still not always adhered to; e.g., the accent for all...