MentalCalculation Minus N Publisher: tatsuya itoh Genre: Board Released: 14 Dec, 2012 Size: 1.8 MB Price: FREE! Click here to request a review of this app App Store Info Description Let's strengthen the brain by the mental calculation. The level is nine. Aim at the best score in the world. What's New in Version 1.1 Trouble was corrected. Screenshots Screenshot 1 of 3