Most CS undergraduate programs in the US suck enough these days that numerical analysis isn't taught at the undergrad level. For example, at my school, undergraduates get to choose between the automata/grammars/computability class and a "numerical methods" class that is really watered down. There is a two-semester undergraduate numerical analysis class, but as I recall it can't count toward your degree except as a general elective. To get numerical analysis to count as a CS elective, you have to take the graduate level class.