Whats the best way to deal with this situation?

Ok well its dese 4 kids n they never take me seriously and there always makin rude jokes about me and insultin my intellegence n this one particular class. at first i just though mhmm they just playin around watevr N i laughed with them but now im gettin tired of it cause they do it soo much N im startin to feel disrespected N i dont appreciate it and want them to stop. I try to ignore em them cant do it very well though.. what should i do about this situation should i tell them off? or play it cool? cause its 2010 N i aint got time for childish axx people!?!???