The lottery method is also called "lottery method". It first numbers each unit of the survey population, and then randomly selects the numbers until enough samples are taken. Generally speaking, the lottery method is to number the n individuals in the population, write the numbers on the digital labels, put the digital labels into a container, stir them evenly, and extract 1 digital labels from them every time, and extract them continuously for n times to get a sample with a capacity of n.
Sometimes it is necessary to use such dice, and the numbers 0-9 on this dice should have the same probability, then a dice with a solid square of 20 can meet the above requirements.
For example, to select 1000 samples from 1000 samples and roll the dice three times, the first number is 100, the second number is 10, and the third number is10 to form a number. Turn the dice repeatedly to get a set of data, which is the number of the sample.