Who doesn’t love a good mystery? The Case of the Missing Number is an addition concepts center that will help your students use bar models to find missing addends and sums.

Directions: Help the detectives solve the Case of the Missing Number! Match the missing parts and sums to the bar models. Complete a record sheet when you are finished.
This printable math center includes the following materials:
- 36 bar model cards (12 missing large addend, 12 missing small addend, 12 missing sum)
- “Directions” page, storage label, and a record sheet
- Color and black & white versions to help you save on ink!

How to use this in your classroom:
- Assign as an individual, partner, or small-group center!
- Engage your students during targeted, small-group instruction!
- Invite students to use when they finish other assignments early!
- Prep your sub plans with ease- called away to a meeting? Unexpected sick day? Your students will love playing this math game individually, in partners/groups, or teacher vs. student on a document camera!
- Fill extra time at the end of a lesson with a meaningful, standards-based activity!
- Print black & white copies to send home with your struggling students for extra practice!
Stop by next Monday for another $1 Math Center Spotlight! More first grade math centers for addition concepts can be found here:

In case you missed it, check out last week’s spotlight about organizing, representing, and interpreting data: Camp Puzzles!
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