Workout :
6.4 -2.351 - 1.45 - 0.999

Answer

To solve the problem \( 6.4 - 2.351 - 1.45 - 0.999 \), we will follow these steps:

### Step 1: Rewrite the Expression
We can rewrite the expression to make it easier to handle:
\[ 6.4 - (2.351 + 1.45 + 0.999) \]

### Step 2: Add the Numbers Inside the Parentheses
Now, we need to add the numbers \( 2.351 \), \( 1.45 \), and \( 0.999 \). To do this, we can align the numbers by their decimal points:

```
2.351
+ 1.450
+ 0.999
```

### Step 3: Perform the Addition
Now, let's add these numbers step by step:

1. **Align the numbers**:
- Add an extra zero to \( 1.45 \) to make it \( 1.450 \).

2. **Add the numbers column by column**:
- Starting from the right:
- \( 1 + 0 + 9 = 10 \) (write down 0 and carry over 1)
- \( 5 + 5 + 9 + 1 (carry) = 20 \) (write down 0 and carry over 2)
- \( 3 + 4 + 0 + 2 (carry) = 9 \)
- \( 2 + 0 + 0 = 2 \)

So, the total sum is:
\[ 2.0 + 9.0 + 0.0 = 4.800 \]

### Step 4: Substitute the Sum Back into the Expression
Now we substitute the result back into the expression:
\[ 6.4 - 4.800 \]

### Step 5: Perform the Subtraction
Now, we subtract \( 4.800 \) from \( 6.4 \):
- Align the numbers:
```
6.400
- 4.800
```
- Subtract column by column:
- Starting from the right:
- \( 0 - 0 = 0 \)
- \( 0 - 0 = 0 \)
- \( 4 - 8 \) (we need to borrow 1 from the 6, making it 14): \( 14 - 8 = 6 \)
- \( 5 - 4 = 1 \)

So, the result of the subtraction is:
\[ 1.600 \]

### Final Answer
Thus, the final answer is:
\[ \boxed{1.6} \]