Please note. The cache is not in the zoo, or any of its surrounding grounds. You do not have to visit the zoo to solve this puzzle.
Now I've got that out of the way, let's go.
Puzzle:
(35/181) + (5*4)
(36/181) + 7
(7*5) + (43/145)
(28/68) + 6
(100/110) + (4*5)
(10*5) + (56/145)
(7*4) + (35/108)
(38/114) + 6
(62/181) + 5
(7*9) + (68/168)
(19/68) + (7*4)
(25/68) + 4
(7*4) + (19/68)