A fun Halloween themed math activity for your class! Students watch a PowerPoint presentation, on your interactive white board, which shows addition and subtraction problems (up to 100 without regrouping.) Students solve each addition or subtraction problem and color in the answer on the accompanying 100 grid. PowerPoint is set to run automatically at 15 seconds per slide. You can adjust the timing to give your students more or less time for each problem. Student directions are on the first slide. Students will need two color pencils/crayons/markers for this activity - black and orange. If the problem is on a black background, color the answer black. If the problem is on an orange background, color the answer orange. Students can make a quick mark on the answer square during the PowerPoint presentation, and then go back to color in fully afterwards. Answer sheet is included! The correct answers will spell out "Boo!" on the 100 grid.