6888.009 - 487.999 - 87.989 = ?

Options

A. a. 6000
B. b. 6570
C. c. 6430
D. d. 6310

Answer

To solve the problem \( 6888.009 - 487.999 - 87.989 \), we will follow these steps:

### Step 1: Subtract the first two numbers
We start by subtracting \( 487.999 \) from \( 6888.009 \).

\[ 6888.009 - 487.999 \]

### Calculation:
Align the numbers for subtraction:

```
6888.009
- 487.999
-----------
```

Now, perform the subtraction:

1. From the thousandths place: \( 9 - 9 = 0 \)
2. From the hundredths place: \( 0 - 9 \) (we need to borrow, so it becomes \( 10 - 9 = 1 \))
3. From the tenths place: \( 0 - 9 \) (borrow again, becomes \( 10 - 9 = 1 \))
4. From the units place: \( 8 - 7 = 1 \)
5. From the tens place: \( 8 - 8 = 0 \)
6. From the hundreds place: \( 6 - 4 = 2 \)
7. From the thousands place: \( 6 - 0 = 6 \)

So, we get:

\[ 6888.009 - 487.999 = 6400.01 \]

### Step 2: Subtract the next number
Now, we subtract \( 87.989 \) from \( 6400.01 \).

\[ 6400.01 - 87.989 \]

### Calculation:
Align the numbers for subtraction:

```
6400.010
- 87.989
-----------
```

Now, perform the subtraction:

1. From the thousandths place: \( 0 - 9 \) (borrow, becomes \( 10 - 9 = 1 \))
2. From the hundredths place: \( 1 - 8 \) (borrow, becomes \( 11 - 8 = 3 \))
3. From the tenths place: \( 0 - 7 \) (borrow, becomes \( 10 - 7 = 3 \))
4. From the units place: \( 0 - 8 \) (borrow, becomes \( 10 - 8 = 2 \))
5. From the tens place: \( 4 - 0 = 4 \)
6. From the hundreds place: \( 6 - 0 = 6 \)

So, we get:

\[ 6400.01 - 87.989 = 6312.021 \]

### Final Answer:
Thus, the final result is:

\[ 6888.009 - 487.999 - 87.989 = 6312.021 \]

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