How many times does the digit 5 appear in numbers 1 to 100?

The digit 5 appears 20 times in the numbers from 1 to 100. It occurs 10 times in the tens place (50 to 59) and 10 times in the units place (5, 15, 25, 35, 45, 55, 65, 75, 85, and 95). Thus, the total count is 20.