Find the difference between the smallest number of 7 digits and the largest number of 4 digits.

Answer

To solve the problem of finding the difference between the smallest number of 7 digits and the largest number of 4 digits, we can follow these steps:

### Step 1: Identify the smallest 7-digit number
The smallest 7-digit number is the smallest number that has 7 digits. This number is:
- **1,000,000** (which is 1 followed by 6 zeros).

### Step 2: Identify the largest 4-digit number
The largest 4-digit number is the largest number that has 4 digits. This number is:
- **9,999** (which is 9 repeated 4 times).

### Step 3: Calculate the difference
Now, we need to find the difference between the smallest 7-digit number and the largest 4-digit number. We can set up the subtraction as follows:
- **1,000,000 - 9,999**

### Step 4: Perform the subtraction
To perform the subtraction:
1. Align the numbers:
```
1,000,000
- 9,999
```

2. Subtract starting from the rightmost digit:
- From the rightmost column: 0 - 9 cannot be done, so we need to borrow from the next column.
- After borrowing, we get:
```
999,991
- 9,999
```

3. Now perform the subtraction:
- 1 - 9 = 2 (after borrowing)
- 9 - 9 = 0
- 9 - 9 = 0
- 9 - 9 = 0
- 9 - 0 = 9
- 0 - 0 = 0

Putting it all together, we get:
- **990,001**

### Final Answer
The difference between the smallest 7-digit number (1,000,000) and the largest 4-digit number (9,999) is:
- **990,001**

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