Comparing Fractions Puzzles CCSS 3.NF.3 and 4.NF.2, serve as a valuable asset to any 3rd grade or 4th grade math classroom. This is a great resource for review, math centers, group work and for interventions. This comparing fractions puzzle set includes 24 puzzles, answer key, and an optional center instruction page. Your students will love learning about comparing fractions (greater than, less than, or equal to) using visual models!