Mental math is all about performing calculations in your mind without the guidance of calculators or other aids. HarryRabby2 Mental Math Challenge is a game that provides you with timed challenges. It provides you with random math subtraction questions of varying difficulty (and with timer limiting the time allowed to seek an answer). You need to click or touch on the correct digits so to formulate a correct answer before HarryRabby falls off the cliff while landing. The game is packed with levels of fun and excitement. There are 5 difficulty levels for you to choose from. Having accessibility in mind, special display and control features are available for low vision gamers. Simple but challenging gameplay, with mobile touch screen support, the games can be downloaded and played on Android mobile devices via Google Play.