If we skip ahead in learning the Girl Scout Law, we come to Flower Friend Clover. The Clover line reads - "use resources wisely." Her story talks of useful ways to use (and reuse) something in order to avoid wasting it. Clover also explains how to find new ways to use old or leftover items.
When you have earned your Clover Petal, you will have practiced using resources wisely. You will be able to read her line in the Girl Scout Law and understand what it means.