IT WILL be recalled that, in algebra, subtraction is merely a special aspect of addition, that multiplication cannot be considered apart from division, and that multiplication itself is merely a rapid kind of addition. In other words, all of these operations are phases of a larger field-the relationships of numbers.
Sears, Paul B.
"SOLVING CONSERVATION PROBLEMS,"
Ames Forester: Vol. 40
, Article 2.
Available at: https://lib.dr.iastate.edu/amesforester/vol40/iss1/2