Missing Part Stories is a free printable Kindergarten maths worksheet on join-change problems, where the change is unknown, aligned to Common Core standard K.OA.A.2. It prints 6 questions with an answer key on its own sheet of paper, in 25 versions that each ask different questions, so no two pupils in the class work from the same page. Print it from the browser or download it as a PDF — no account, no email.

Last reviewed 2026-09-05. Aligned to K.OA.A.2 of the Common Core State Standards for mathematics.