A public service (that usually lasts all year) in which you voluntarily take time out of your day to help your buddy pass math class. Most common math pro bono's involve one American student and the foreign kid he's grown fond of and befriended.
Foreign Kid: "Yo dude I don't get this shit! What the fuck is teach talking about when he says cosine of 30 degrees?"

American Kid: "Get your calculator. All you gotta do is put in 'cos(30degrees)' and you'll get '0.866025404'. Simple dude. Are you going to be my math pro bono all damn year?"

Foreign Kid: "Yeah dude, we don't do math in my country."
by westfalia January 12, 2010
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