This common core activity can be used by anyone who needs to practice or review finding common denominators for unlike denominators of fractions. The activity can be used a an individual, partner, small group, math center, math station, or take-to-desk folder activity. Just take your pick! The object of the activity is to compare sets of cards, (6 cards to a set), by changing the unlike denominators to common, or like, denominators. The activity includes cover page, teacher and student directions, 6 sets of Order Up! cards, (6 cards to each set), a Recording Sheet, an Answer Key, and 3 title pages, (Math Center, Math Station, Take-to-Desk Folder Activity), in case you wish to use the activity in any or all of these 3 ways.