Looking for 3-digit addition with regrouping worksheets for Grade 3, Grade 4, or Grade 5? These Math Detective Mysteries are engaging back-to-school math activities that help students build confidence with triple digit addition, problem solving, and logical reasoning through an interactive math mystery format. This resource includes three printable Math Detective Mysteries, each designed to be completed in one class period. They work well for beginning-of-the-year math review, math centers, earl