MATH
posted by MELISSA .
NEED HELP WITH SUMMATION NOTATIONS
TOP NUMBERIS 6 OVER A SIDEWAYS Z BOTTOM NUMBER IS A N=2 THAN THERE IS (2N1) NEED TO KNOW HOW TO WORK THIS PROBLEM. i AM TRYING TO HELP MY SON WITH HIS HOMEWORK

looks like you are describing Sigma notation.
here is a webpage that explains it in the first 2 pages.
http://www.mathcentre.ac.uk/resources/leaflets/firstaidkits/2_22.pdf
for yours it can be expanded to
3 + 5 + 7 + 9 + 11
at this point just add them up