例：用筛选法求2～100之间的所有素数。

解：我们用下面的方法来解这题：先建立一个含有2～100之间所有自然数的数表，在数表中删去2的倍数(不包括2)；然后找2后面第一个被保留的数p(是3)，再删除p的倍数(不包括p)；然后再找下一个被保留的数(是5)，继续上述步骤：这样继续下去，直至P大于100为止。这样数表中剩下的数就是所要求的所有素数。这个求素数的方法称为爱拉托散(Eratosthenes)法。

-Example: Method 2 with the screening of all prime numbers between 100. Solution: We use the following method to solve this problem: first the establishment of a containing between 2 to 100 the number of all natural numbers table, delete table 2 in the number of multiples (not including 2)　and then find the back of the first to be reserved 2 number p (a 3), then delete multiple of p (excluding p)　and then find the next number to be reserved (was 5), continue the steps: continue to do so until the P is greater than 100 so far. So that the remaining number of tables is required for all prime numbers. This request is called Ai Latuo prime numbers scattered (Eratosthenes) method.