Can you use % in scripts?
Yes, but not exactly for percentages, I don't think. If you're looking to use percentages, use decimals or fractions.
% does an operation that is the remainder of division.
For example, 14%6 =2, because 6 goes in to 14 twice, and it has a remainder of 2. 12%6=0 because 6 goes in to 12 twice, and it has a remainder of 0.