This Earth Day themed PowerPoint game reviews the concepts of two digit addition and subtraction with/without regrouping. The game includes three rounds:

ROUND 1: The students will solve twenty two-digit addition/subtraction problems with/without regrouping. They are encouraged to use their strategies as well as scrap paper or a dry erase board to show their work. All of these problems are multiple choice and the answers are given after each problem for instant feedback. The teacher can also have the students use error analysis and have the students figure out the reason why an incorrect answer was wrong.

ROUND 2: The students will solve five Earth Day themed word problems.

ROUND 3 - THE LIGHTENING ROUND: This round will be like electronic flash cards. A number sentence will appear on the screen. The students can say the answer or write it down before the teacher reveals the answer on the following slide. There are sixteen number sentences in this round.

This activity can be used as an independent center, team game, or whole group with the students solving the problems on their own and then checking them together as a class.