Illustrative MathematicsVaries

An even number is an integer that is a multiple of 2 while an odd number is an integer that isn't even. In second grade students have not yet learned about multiplication and division (much less factors and multiples), so standard 2.OA.3 calls for students to determine whether a set of objects contains an even or odd number of members using strategies that reflect a grade-appropriate understanding of even and odd. These strategies, such as pairing objects or attempting to divide the objects into two equal subgroups correspond to the 'number of groups unknown' and 'group size unknown' interpretations of division by 2 that students will study in more depth in third grade. This task is specifically written so that students have opportunities to use different strategies to determine whether a set has an even or odd number of objects.