Math worksheet for practicing subtraction of 5-digit numbers from 6-digit numbers with regrouping, focusing on finding missing digits.

To solve the problem, we need to fill in the missing digits in each subtraction problem. Let's go through each one step by step.

Problem 1:

```
3999□0
- □4681
---------
□1530□
```

#### Step-by-step solution:
1. Units place:
- The result is `0`. Since `0 - 1` requires borrowing, the digit above must be `10 - 1 = 9`.
- So, the units digit of the minuend is `9`.

2. Tens place:
- After borrowing, the tens digit of the minuend becomes `8` (from `9`).
- The result is `0`. Since `8 - 8 = 0`, the tens digit of the subtrahend is `8`.

3. Hundreds place:
- After borrowing, the hundreds digit of the minuend becomes `8` (from `9`).
- The result is `3`. Since `8 - 6 = 2`, and we need `3`, we borrow again.
- So, the hundreds digit of the minuend is `9` (after borrowing).

4. Thousands place:
- After borrowing, the thousands digit of the minuend becomes `8` (from `9`).
- The result is `5`. Since `8 - 4 = 4`, and we need `5`, we borrow again.
- So, the thousands digit of the minuend is `9` (after borrowing).

5. Ten-thousands place:
- After borrowing, the ten-thousands digit of the minuend becomes `2` (from `3`).
- The result is `1`. Since `2 - 2 = 0`, and we need `1`, we borrow again.
- So, the ten-thousands digit of the minuend is `3` (after borrowing).

6. Hundred-thousands place:
- The hundred-thousands digit of the minuend is `3`.

7. Subtrahend:
- The subtrahend is `24681`.

So, the completed subtraction is:
```
399990
- 24681
---------
375309
```

Problem 2:

```
□5595
- 4058□
---------
3□5109
```

#### Step-by-step solution:
1. Units place:
- The result is `9`. Since `5 - □ = 9`, we need to borrow.
- After borrowing, `15 - □ = 9`, so `□ = 6`.

2. Tens place:
- After borrowing, the tens digit of the minuend becomes `8` (from `9`).
- The result is `0`. Since `8 - 8 = 0`, the tens digit of the subtrahend is `8`.

3. Hundreds place:
- After borrowing, the hundreds digit of the minuend becomes `4` (from `5`).
- The result is `1`. Since `4 - 5 = -1`, we need to borrow.
- So, the hundreds digit of the minuend is `5` (after borrowing).

4. Thousands place:
- After borrowing, the thousands digit of the minuend becomes `4` (from `5`).
- The result is `5`. Since `4 - 0 = 4`, and we need `5`, we borrow again.
- So, the thousands digit of the minuend is `5` (after borrowing).

5. Ten-thousands place:
- After borrowing, the ten-thousands digit of the minuend becomes `4` (from `5`).
- The result is `3`. Since `4 - 4 = 0`, and we need `3`, we borrow again.
- So, the ten-thousands digit of the minuend is `5` (after borrowing).

6. Hundred-thousands place:
- The hundred-thousands digit of the minuend is `4`.

So, the completed subtraction is:
```
45595
- 40586
---------
395109
```

Final Answer:

```
399990
- 24681
---------
375309

45595
- 40586
---------
395109
```

The final answer is:
\boxed{375309, 395109}