This pdf includes one center for determining a missing angle. I used this in correlation with the NYS Fourth Grade Math Module 4, which is about geometry. These could be used in other grades as well to increase fluency, challenge students in younger grades, or to help students who struggle in higher grades. In this center, students take a card and use what they know about angles to solve for a missing angle (in some cases, there is more than one missing angle). Some of the cards are word problems, where students will need to think about the information in order to solve for the missing angle(s). Other cards have angles drawn on them that will assist the students in determining the missing angle.
These are aligned with the common core state standards 4.MD.C.5 and 4.MD.C.7.
This center has 32 cards, which are numbered.