This is one of my favorite ways to review and practice double and triple digit addition and subtraction. (with and without regrouping) The crazy "mad mathematician" leaves the class a clue or even might show up to "lock" the class in unless they are able to solve the math problems left around the room. This is a lot of fun as the students try to solve the problems on their worksheet. The students must complete a problem completely before moving on to the next card. They will locate the next card by the answer to the problem. They are all linked until the final answer. When they think they have completed all of the problems they show their teacher their work and see if it they are able to unlock the room by getting the "key." Students even get a picture with their certificate that says "I escaped the room!" This is a lot of fun and a great mix of problems to solve.
Grey cards: Includes a mix of problems with regrouping and without regrouping, addition and subtraction. The problems are triple and double digit word problems. There are also problems with multiple double digit numbers to add. Sometimes students solve to find the missing number.
Yellow cards:Includes no regrouping. There are double and triple digit addition and subtraction.