1. Think of a domino and count the number of pips
on the left side of that domino.
2. Multiply this number by 5.
3. Add 7.
4. Multiply by 2.
5. Add the number of pips on the right side of the domino.
Click here to run again
Click here to see why it works
Many thanks to Jaime Garcia Ramirez for helping me with the javascript!