The expression (2*3) literally means ... A. (2 + 2 + 2) or... B. (3 + 3) Therefore it is a factual statement to make, that in the original expression (one) of the given numbers does not exist. If we chose (A) the number 3 does not exist. If we chose (B) the number 2 does not exist. So then what is "it" that exist? If we chose (A) it is the number (2) inside a quantity of (3) spaces. If we chose (B) it is the number (3) inside a quantity of (2) spaces. Therefore it is factual statement to make, that all numbers are composed of a numerical quantity, and a dimensional quantity. If then "units" are by definition dimensions. Then it is a true statement that absract numbers "contain" absract units. Therefore the only real definition of "numbers" is the "concrete" definition. Where as the units for concrete numbers are not absract, and the units for absract numbers are absract.