Using a long stip of paper that is numbered in regular intervals from 0 to 100, have children point to and identify percents of the whole. For example - 10% would include the number 1 and everything left of it. 50% would include the number 5 and everything left of it. You can also have the students work in groups. Each child writes down different percents on small pieces of paper and then exchanges with their partner. The other student must stick the percents on the number line appropriately.