Pages in a book are numbered from 1 to 1001. How many times does the digit 0 appear
To determine how many times the digit 0 appears, we can analyze the number of times it appears in each place value.
In the units place, there are 100 digits numbered 0, 10, 20, ..., 990, 1000, so the digit 0 appears 100 times.
In the tens place, there are 10 digits numbered 00, 01, 02, ..., 99, so the digit 0 appears 10 times.
In the hundreds place, there are 10 digits numbered 000, 001, 002, ..., 099, so the digit 0 appears 10 times.
In the thousands place, there are 1 digit numbered 0000, so the digit 0 appears 1 time.
Therefore, within the numbers 1 to 1001, the digit 0 appears 100 + 10 + 10 + 1 = 121 times.