Ocean math code breaker mixed addition and subtraction worksheets no regrouping! Students solve 3–4 digit addition and subtraction WITHOUT regrouping, then crack the code to reveal fun ocean facts. 10 printable worksheets, no prep, self-checking + answer keys.In this Ocean Facts Math Code Breakers set, students solve 3-digit and 4-digit addition & subtraction without regrouping. Each correct answer matches a letter in the code, and the letters reveal a hidden ocean fact. What’s included 10