When adding quantities manually, it would helpful if units could be parsed directly.
This at least when there are preferred units defined on a property and the abbreviation given matches this.
Sample:
*enter "10 m" in a statement for height (P2048)
*https://www.wikidata.org/wiki/Property:P2048#P2273 lists Q11573 as one of the units for the property
*https://www.wikidata.org/wiki/Q11573#P558 has a couple of unit symbols, including "m"
*So, "10 m" should result in 10 with unit Q11573