`105.003+307.993+215.630=?`

Options

A. 610
B. 650
C. 660
D. 630

Explanation

To solve the problem \( 105.003 + 307.993 + 215.630 \) using approximation, we can follow these steps:

### Step 1: Approximate Each Number
- **For 105.003**: Since the decimal part (0.003) is less than 0.5, we can approximate it to **105**.
- **For 307.993**: The decimal part (0.993) is greater than 0.5, so we round it up to **308**.
- **For 215.630**: The decimal part (0.630) is also greater than 0.5, so we round it up to **216**.

### Step 2: Write the Approximate Sum
Now we can write the approximate sum:
\[ 105 + 308 + 216 \]

### Step 3: Calculate the Sum
- First, add \( 105 + 308 \):
\[ 105 + 308 = 413 \]
- Next, add \( 413 + 216 \):
\[ 413 + 216 = 629 \]

### Step 4: Choose the Closest Option
Since the exact sum is 629, we look for the closest option. The options available are likely to be around this number. The closest option to 629 is **630**.

### Final Answer
Thus, the approximate sum of \( 105.003 + 307.993 + 215.630 \) is **630**.

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