Give your students engaging practice with 3-digit addition and subtraction with regrouping worksheets in a fun Math Mystery format. Designed for 2nd grade, 3rd grade, and 4th grade math, these printable activities combine regrouping practice, problem solving, and mystery stories that capture student interest. Each worksheet begins with a short story, followed by 16 regrouping questions that guide students in eliminating suspects until the mystery is solved. These math mystery worksheets ar