`7.125-4.309=?`

Answer

To solve the problem \( 7.125 - 4.309 \), we will follow these steps:

### Step 1: Align the numbers
Write the numbers one below the other, aligning the decimal points:

```
7.125
- 4.309
```

### Step 2: Subtract the digits starting from the right
We will subtract each column starting from the rightmost digit:

1. **Thousandths place**:
- We have \( 5 - 9 \). Since 5 is less than 9, we need to borrow from the next column.
- Borrow 1 from the 2 (which becomes 1), making the 5 become 15.
- Now, \( 15 - 9 = 6 \).

2. **Hundredths place**:
- Now we have \( 1 - 0 = 1 \) (since we borrowed 1 from the 2).

3. **Tenths place**:
- We have \( 1 - 3 \). Since 1 is less than 3, we need to borrow from the next column.
- Borrow 1 from the 7 (which becomes 6), making the 1 become 11.
- Now, \( 11 - 3 = 8 \).

4. **Units place**:
- Finally, we have \( 6 - 4 = 2 \).

### Step 3: Combine the results
Putting it all together, we have:

```
7.125
- 4.309
--------
2.816
```

### Final Answer
Thus, \( 7.125 - 4.309 = 2.816 \).

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