The difference between 6-digit smallest number and 4-digit largest number is:

Options

A. 90001
B. 91000
C. 90100
D. 90010

Answer

To solve the problem, we need to find the difference between the smallest 6-digit number and the largest 4-digit number.

### Step-by-Step Solution:

1. **Identify the smallest 6-digit number:**
- The smallest 6-digit number is 100000. This is because a 6-digit number cannot start with 0, so we start with 1 followed by five 0s.
- **Hint:** The smallest 6-digit number is formed by placing the smallest non-zero digit in the highest place value and filling the rest with zeros.

2. **Identify the largest 4-digit number:**
- The largest 4-digit number is 9999. This is because the largest digit is 9, and using it in all four places gives us the maximum value.
- **Hint:** The largest 4-digit number is formed by using the largest digit (9) in all four positions.

3. **Calculate the difference:**
- Now, we need to find the difference between the smallest 6-digit number (100000) and the largest 4-digit number (9999).
- We perform the subtraction:
\[ 100000 - 9999 \]

4. **Perform the subtraction:**
- Align the numbers for subtraction:
```
100000
- 9999
---------
```
- Start subtracting from the rightmost digit:
- 0 - 9: We need to borrow. So, we take 1 from the next column (which becomes 10), making it 10 - 9 = 1.
- Next column: 0 (after borrowing) - 9: Again, we borrow, making it 10 - 9 = 1.
- Next column: 0 (after borrowing) - 9: Borrow again, making it 10 - 9 = 1.
- Next column: 0 (after borrowing) - 9: Borrow again, making it 10 - 9 = 1.
- Next column: 0 - 0 = 0.
- Last column: 1 - 0 = 1.
- So, the result of the subtraction is:
\[ 90001 \]

5. **Final Answer:**
- The difference between the smallest 6-digit number and the largest 4-digit number is **90001**.