Complex sentence: Other measures use a numerical scale of attractiveness, wherein 1 is the ugliest while 10 is the most attractive, whereby the most unattractive individuals would be described as "1s", "2s" and "3s".
Split into simpler sentences: Other measures use a numerical scale of attractiveness, wherein 1 is the ugliest while 10 is the most attractive. Herewith the most unattractive individuals would be described as "1s", "2s" and "3s".