2. How many three-digit numbers do not contain the digit 8?
2. First method of solving. There are a total of 900 three-digit numbers. To find out how many of them do not contain the digit 8, we need to subtract from 900 the number of three-digit numbers that contain the digit 8. Let's determine the number of these numbers. From 800 to 899, there are one hundred such numbers. Other numbers containing the digit 8 will be $152=19 \times 8$. Thus, the number of numbers that do not contain the digit 8 is $648(900-100-152=648)$.

Second method of solving (Sergey Podkovinsky, student of School No. 46).

From 100 to 199, there are a total of 100 numbers. Nineteen of them contain the digit 8.

$100-19=81$ numbers - in the hundred do not contain the digit 8. There will be eight times 81 such numbers.

Numbers from $800-899$ should be excluded as they all contain 8. As a result, we get

$$
81 \times 8=648 \text { numbers. }
$$

Answer: 648 numbers.