•8. When a quantity is expressed as a number and unit, and is used as an adjective, then a hyphen separates the number and unit. For example: The 3-m rod broke.
•9. The product of two or more unit symbols may be indicated with a raised dot or a space. (N.m
or N m).
•10. The product of two or more unit names is indicated by a space (preferred) or a hyphen.