While we were ‘discovering’ negative numbers seeing the ballerina dancing past zero on the number line, I saw a smile start on the face of one of the students and at one point during the activity she raised her hand and said excitedly: “Look! We are entering the world of the opposites!”. I could not help but laugh and replied, “it’s true, isn’t that cool?”, she nodded and continued to explore that new ‘world’ that she was seeing…