As you review numerators and denominators with your students, have them look at their circles and ask them to take out a certain amount of pieces from their circles and count them. For instance, if they take out 2 pieces from the circle that has 6 parts, what number would the numerator be for the pieces they removed? Have the students count the two pieces and realize that the number 2 would be the numerator. Have the students count the rest of the pieces and understand that 4 would be the numerator for those. Review and perform these exercises with your students until they seem to understand the concept of writing fractions. To further enforce the idea, pick a student for each question to come and write the fraction on the board.