Here is a fun and engaging way for students to practice arithmetic sequences. Students will continue a sequence and find the missing numbers by determining the common difference. If a student answers correctly, his answer cell will change to his assigned color, and the opponent's cell will also change to that color, locking him out from answering. There are 20 questions, and the game is SELF-GRADING and available in Google Sheets. The game can be played on one device between two students or played on two separate devices. An answer key is included.