There are so many ways to use the Snowball strategy that is on my Classroom Strategies page.
Here is a simple way to turn learning about percentages into a fun activity using the snowball strategy.
After some initial input in which learners learn how to perform simple percentage calculations use the snowball strategy (a copy of one is at the bottom of this page) to enhance their understanding.
As you will see from the file, one student has the question and they have to find their partner who will have the answer.
When everyone has found their partner, you can have them stand in a cirlce and get each pair to read out their question and answer to check they have the right combinations.