Check out these free games created by Reagan from Tunstall's Teaching Tidbits....
How cute are these Monsters? They would make a great math station game for the month of October. The age range for these is K-2, however I would not hesitate to use them with my fourth graders. Believe me, they can always use the practice of putting together two number to equal 10 or 20. This would also be a great activity to use with your intervention students.
This math game is similar to concentration and my card game Turn Over 10. Students flip over the cards make matches that when added together equal 10.
Here is the more advanced version of Monster Math. For this one students have to make matches that equal 20.