I didn't know what did your teacher say but I think he mean nought . Nought mean Zero or nothing. Sometimes they use it in Mathematics.

what do you say? :)

Thanks Peachey and Nanren, it is algebra, and it is used to denote the initial state, at first I thought she was saying "U oh", but then I noticed she always pronounce the zero by starting with an "n" sound, like "no", so, based on Comandante and Peachey, i think it should be nought. :)

Stan, What did she say? ....."U0" is written. What did she actually say? "You zero"? "You nought" does not seem to make sense either. . ... Is this algebra? Are there variables, u0, u1, u2, u3?,,, In maths & physics, often initial conditions are identified with a "0" [zero] appended. The car moves from position p0 to position p1 over time t.

I agree with Comandante. Based on the context, it was most likely "nought".