Train your Brain cards were developed to reinforce a variety of math concepts at each age level. Train your Brain questions encourage mental fluency and reasoning in four areas: Counting, Money, Time and "Grab Bag" (a mix of concepts that include geometry and measurement as well as concepts that require number sense). Each card has six questions which are read aloud for a child to solve and answer without the use of pencil and paper (answers are provided on the card). Each card increases with difficulty until the last (11th) card. Parents/caregivers can (and should) repeat cards to reinforce mental fluency. To increase difficulty, the length of time given to answer each question can be shortened. Blue level cards include a number grid for children to use at the beginning as well as additional instruction on how to introduce concepts of money.