------
## 最终结论
```python
def count_Hexadecimal(start, end):
    count = 0
    for num in range(start, end + 1):
        if 0 <= num <= 15:
            count += 1
    return count

# Test cases
assert count_Hexadecimal(10,15) == 6
assert count_Hexadecimal(2,4) == 3
assert count_Hexadecimal(15,16) == 2
```