The root ᴹ√RÁSAT “twelve” appeared in The Etymologies of the 1930s, and students of Elvish long supposed that its unattested derivative *rasta was the Quenya word for “twelve”. In later publications, however, the Quenya word for “twelve” was given as yunquë (VT47/41), derived from primitive ✶yūnekē.

This word yunquë dates back to Early Quenya, first appearing as ᴱQ. yunqe in the Early Qenya Grammar from the 1920s (PE14/82), so it is likely that the √RASAT “twelve” co-existed with ✶yūnekē when that root was introduced in the 1930s. In currently published materials, rasta only appears as a suffix in yurasta “twenty four” (twice-twelve) in a discussion of the Elvish duodecimal (base twelve) counting system, also probably from the 1930s (PE14/17). It may be that ✶yūnekē was used for the general word for “twelve”, while √RASAT was used for “groups of twelve” as part of this duodecimal system. If so, it may have only been used as a suffix in grouping words in this counting system.