Brain Age Check Selection Go to the Daily Training section and select your name, press and hold SELECT and pick Brain Age Check. This will open up a selection menu that lets you choose which three challenges you want to complete for the age check. Hard mode for Calculations x 100 game Collect 11 stamps. Hard mode for Head Count game Collect 9 stamps. Low to High game Collect 1 stamp. Head Count game Collect 3 stamps. Hard mode for Triangle Math game Collect 17 stamps. Voice Calculation Game Collect 20 stamps.