The One in the Middle Is the Green Kangaroo — Judy Blume

Lately second grader Freddy Dissel has that left-out kind of feeling. Life can be lonely when you're the middle kid in the family who feels like "the peanut butter part of a sandwich," squeezed between an older brother and little sister. But now for the first time it's Freddy's chance to show everyone how special he is and, most of all, prove it to himself!