Home/Curriculum/Unit 5 Inventor LabUnit 5·Lesson 5B.3Tic-Tac-Toe: Placing the MarksPick a square, place your mark. It starts to feel like a game.Inventor Lab · Tic-Tac-ToePrevious5B.2 · Tic-Tac-Toe: Drawing the BoardNext5B.4 · Tic-Tac-Toe: Two Player Tic-Tac-ToeLesson 5B.3Back to Unit 5