Emanuele Feronato shows the source code for DrawSum, a HTML5 math game: "Three years ago I developed a math game called DrawSum for a learning project.
It was a mix between a draw and match game based upon Dungeon Raid engine and a pure math game.
I used Phaser 2.4.8, but it’s perfectly compatible with latest Phaser CE release and you can easily port to Phaser 3 or any other language if you prefer (I am about do it)."