To find a percentage, divide the number of times something occurred by the total number of possible occurrences and then multiply by 100. If a player made nine of 10 shots, divide nine by 10 and get 0.9. Multiply 0.9 by 100 to get 90 percent.
Assume Johnny got 34 correct answers out of 50 total questions. To figure out his percentage of correct answers, first divide 34 by 50. The result is 0.68. Multiply that number by 100, and the result is 68 percent. If something happens 15 out of 15 times, divide 15 by 15. The result is 1.0 times 100, or 100 percent.