Talk about pie and pizza slices when introducing this topic. Give each student or group pages with circles predrawn/printed on them and divided as identified below. To make it easier for you, use a different colored paper for each. Have them cut the circles apart along the lines you provide. Divide circle 1 into 1 half piece, 1 quarter piece and 2 one eigths pieces. Circle 2: 1 half piece, 1 one third, and 2 one sixth pieces. Circle 3: 1 half piece, 5 one fifth pieces. Circle 4: Don't divide the circle and have the children leave the page whole. Make sure each piece was pre-printed with the appropriate measurement. Now ask the kids to assemble the pieces into the fractions you ask for and have them assemble the pieces on the unlined circle. The different colors will make it easier for you to see if the children are doing it correctly.