Answer:
 8 crackers
Step-by-step explanation:
You want to know the number of 2-inch round crackers 0.2 inches high required to make a volume of 5 cubic inches.
Volume
The volume of one cracker is ...
 V = πr²h . . . . . where r is half the diameter
 V = π(1²)(.2) ≈ 0.6283 . . . . cubic inches
Crackers
If n is the number of crackers, their volume will be ...
 0.6283n = 5
 n = 5/0.6283 ≈ 8
There are 8 crackers in the stack.
