Basically to determine the number of drinking glasses that Chelsea needs, use the proportion ratio given in the problem and either cross multiply or find a number that will multiply to give the number of boxes that Chelsea will need.
1 box = 6 glasses
? boxes = 514 glasses
(514 glasses * 1)/6 = ?
? = 85.6, so she would need about 86 boxes in total to store a total amount of 514 drinking glasses, assuming that a single box can store 6 drinking glasses.