Triple digit Addition with Regrouping Activity #1 This paperless math center includes 30 interactive Slides and a Self-Grading Google Form for students to practice adding 3 digit numbers up to 1,000 with regrouping. The activity includes 20 slides with movable Base 10 Blocks for students to practice regrouping using a place value strategy as well as 10 slides with standard algorithm practice problems. The resource includes a TIME SAVING Self-Grading Google Form to provide students wi