Editing Addition (section)

=== Units ===
To numerically add physical quantities with [[units of measurement|units]], they must be expressed with common units.{{sfnp|Fierro|2012|loc=Section 2.3}} For example, adding 50&nbsp;milliliters to 150&nbsp;milliliters gives 200&nbsp;milliliters. However, if a measure of 5&nbsp;feet is extended by 2&nbsp;inches, the sum is 62&nbsp;inches, since 60&nbsp;inches is synonymous with 5&nbsp;feet. On the other hand, it is usually meaningless to try to add 3&nbsp;meters and 4&nbsp;square meters, since those units are incomparable; this sort of consideration is fundamental in [[dimensional analysis]].<ref>{{Cite book|last1=Moebs|first1=William|url=https://openstax.org/books/university-physics-volume-1/pages/1-4-dimensional-analysis|title=University Physics Volume 1|last2=Ling|first2=Samuel J.|publisher=[[OpenStax]]|year=2022|isbn=978-1-947172-20-3|chapter=1.4 Dimensional Analysis|display-authors=1}}</ref>