This was sooooo cooool!
Check out the video on this trick.
The "Coin Math" app has introduction, matching, counting, shopping, and making change. All are good. I am going to start with Match the Coins.
The "Penny Me" app is good to introduce counting coins.Penguin Jump is perfect to give students time to practice their multiples of 3 and 4's.
Students can create a private game and then choose custom, with numbers 3 and 9.