What is the exclusion method of lottery tickets?

Exclusion method is a common method in lottery, which refers to a method to exclude the impossible number selection according to the conditions and types of lottery number selection. For example, let's take 3D or the third row as an example. Let's choose four yards, 2345, and we need 8 yuan to make it into a single note, that is, four notes, 234, 235, 245 and 345. For example, if we are optimistic that 2 can't get out today, we will rule out 2 first. Among the first four note numbers, only 1 meets the requirements. It used to cost 8 yuan, but now there are only 2 yuan left, so this method is very common and practical in lottery.