Hello, I am curious as to why the abreviation of the word number is no. Why is it not nu.?
Like a number of our abbreviations, no. actually abbreviates a Latin word, numero, which, for the grammar buffs amongst us, is the ablative singular of numerus, "number."
Some other Latin-based abbreviations: lb. from Latin libra "measure of weight, pound"; a.m. and p.m. from ante meridiem and post meridiem, "before noon" and "afternoon". The abbreviation for ounce, oz., is from onza, the Italian form of Latin uncia. The cross- referencing abbreviation, q.v., is from quod vide, "which see." Amongst the footnotes we find some others: ibid., from ibidem, "in the same place"; op cit., from opere citato, "in the work cited."
One last one: the abbreviation for prescriptions, either Rx or a large R with a crossed right leg, is from Latin recipe, recipio, "take." One theory is that the cross-legged R is based on the sign of the god Jupiter and was used to propitiate the god by making the prescription.