It is a game which answers the answer before the number of times of specifying. In the case of 3 times before example 1+1=2 <- memory 2+2=4 <- memory 3+3=6 <- memory 4+4= #2 <-The answer 3 times before and the answer of 4+4 is memorized. 5+5=#4 <-The answer 3 times before and the answer of 5+5 is memorized. There is a random choice 1-7 times ago. They are the gymnastics of the head.