Krishna wrote 1 to 100 numbers, the frequency of the digit 9 is___________

Answer

To find the frequency of the digit 9 in the numbers from 1 to 100, we will analyze each number and count how many times the digit 9 appears.

### Step-by-Step Solution:

1. **Identify the Range**: We are looking at the numbers from 1 to 100.

2. **Count Occurrences of 9 in Each Decade**:
- **From 1 to 9**: The only number is 9. (Count = 1)
- **From 10 to 19**: The number 19 contains one 9. (Count = 1)
- **From 20 to 29**: The number 29 contains one 9. (Count = 1)
- **From 30 to 39**: The number 39 contains one 9. (Count = 1)
- **From 40 to 49**: The number 49 contains one 9. (Count = 1)
- **From 50 to 59**: The number 59 contains one 9. (Count = 1)
- **From 60 to 69**: The number 69 contains one 9. (Count = 1)
- **From 70 to 79**: The number 79 contains one 9. (Count = 1)
- **From 80 to 89**: The number 89 contains one 9. (Count = 1)
- **From 90 to 99**: The numbers 90, 91, 92, 93, 94, 95, 96, 97, 98, and 99 contain one 9 each. The number 99 contains two 9s. (Count = 11)

3. **Total Count**: Now, we sum up all the counts:
- From 1 to 9: 1
- From 10 to 19: 1
- From 20 to 29: 1
- From 30 to 39: 1
- From 40 to 49: 1
- From 50 to 59: 1
- From 60 to 69: 1
- From 70 to 79: 1
- From 80 to 89: 1
- From 90 to 99: 11

Total = 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 11 = 20

4. **Conclusion**: The frequency of the digit 9 in the numbers from 1 to 100 is 20.

### Final Answer:
The frequency of the digit 9 is **20**.