Elena's daughter sold 84 boxes of girl scout cookies. she was told that this amount represented 5% of the troop's sales. how many boxes did the troop sell?

Elena's Daughter sold 84 boxes, 84 boxes are 5% of the number of boxes the troop sold.
There are couple ways to solve this problem, here's how I would do it:
84 = 5%
1% = ?
1% =  = 16.8
100% = 16.8 × 100
100% = 1680

The troop sold 1640 boxes of girl scout cookies.