Included in this set are sixteen addition and sixteen subtraction task cards. They are three and four digit algorithm problems with regrouping. This would be a good task for advanced or late in the year 2nd graders, for 3rd grade, and review at the beginning of 4th grade. They can also be used in home schooling. Also included is a sheet that is reproducible on which students can write the answers to the problems. An answer key is also included. Teachers can put the task cards around the room and give students a number of problems to solve. More suggestions on how to use this resource is included with the materials.