It looks like they charged you tax on each individual item. From the Florida Sales Tax schedule,
http://floridarevenue.com/Forms_libr...rrent/dr2x.pdf
The taxes are:
.04 on each of the two senior drinks = .08
.07 on the curly fry = 0.7
.12 on each of the three classic RB = 0.36
Total = $0.51 tax