These task cards focus on the second grade Common Core Math Standard 2.OA.3: I can group objects to tell if a number is even or odd. “A Day at the Zoo – Even or Odd Task Card Sort,” is a task card sorting activity that can be used by a small group of students or individual students. I love task cards because they can be used for a practice activity, a game, or even an assessment. If you print the task cards on cardstock, they should last all year. Of course, you can laminate them to make them even more durable.