There is a very simple method to guess the red figure, in this first you see that the pair is divided into the same figure, for example, such numbers as 11,22,33,44,55,66,77,88,99,00 are red numbers and from 1 to 6 , 6 to 1, 2 to 7 , 7 to 2 , 3 to 8 , 8 to 3 , 4 to 9 , 9 to 4 , 5 to 0 , 0 to 5 , They are in the feet of 20, you can easily guess by looking at them, these are red numbers.