Two Digit Addition and Subtraction with Regrouping These puzzles are the perfect way to challenge your students or engage your fast finishers. Students solve the problems and then enter their answers into the grid. It's like a crossword puzzle but with numbers. The intersecting problems provide a self-checking feature. Thanks to the intersecting problems, these cross-number puzzles have a self-checking feature (incorrect answers won't match up with other answers in the puzzle). This product