Back to School 3-Digit Addition
Mystery Detective Worksheets · Grades 2–5
Sold on Teachers Pay Teachers, where your purchases and downloads are kept.
Inside the case file
Back to school 3 digit addition with regrouping worksheets for 2nd grade, 3rd grade and 4th grade, set out as five printable CSI Mini Mystery Detective cases. Students carry across three digit columns, match each total to a clue and cross a suspect off until one is left. These are no prep August and September math activities for math centers, morning work, early finishers, homework and sub plans, print and go from the first page. One download holds five school themed cases, a full black and white set and answer keys, ready for the first week back.
Three digit carrying is the first thing a long vacation takes away, and the first weeks back are when you need to see where a class actually is without spending a lesson on it. A case does that quietly: a wrong total matches no clue, so the page tells the student before it tells you, and you get to watch who is checking and who is guessing.
The Cases
- Welcome Back Cake for the Teachers - who made it
- The Missing Pens - somebody has taken them
- New Student to the School - working out who is who
- Showing Mindfulness - a count that does not add up
- Math Book Not Named - the last case of the set
What's Inside
- Five color case pages, sixteen addition problems on each
- The same five cases again in black and white
- An answer key for every case
- A color in page for early finishers
- A teacher instruction page, print and go with nothing to prepare
- Three digit addition with regrouping throughout
What Is a CSI Mini Mystery Detective?
One printed page holding one crime and the clue list that solves it. Each clue carries a number, the sixteen sums on the page produce those numbers, and a correct total knocks a clue out. Work to the last question and a single suspect is left standing. Get a column wrong and nothing matches, which sends a student back over their working before you ever see it.
When to Use This Resource
Reach for this in the first weeks of the year, once three digit addition has been taught and simply needs keeping warm, and again as a refresher after any long break. It works as homework, as a center, and as a set to leave for a substitute. Use it for math centers, morning work, early finishers, homework, sub plans and homeschool lessons, with a whole class, a small group or one student.
Grade Levels
Written for 2nd grade, 3rd grade and 4th grade. Fifth graders who still need column addition firmed up get plenty out of it, and confident second graders manage it with a little support.
Why Teachers Love These Cases
- A wrong total matches no clue, so students catch their own slips
- Color and black and white are both in the download
- A color in page for whoever finishes first
- Five cases covers the whole first week back
Love this resource?
Follow Kiwiland Education to discover more CSI Mini Mystery Detective cases, no prep math activities, and detective themed printables for elementary classrooms.
https://www.teacherspayteachers.com/Sellers-Im-Following/Add/Kiwiland
