We're dividing 864651 by 51 
Let's see how many times 51 fits into 864651.

Step 1:
8 divided by 51 is 0 with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 8 to get 8.
Include the next digit (6) from the dividend after 8, then repeat: 86 / 51

Advancing to step 2:
When dividing 86 by 51, we get 1 with a remainder of 35.
The next digit of our result is 1. 
Result so far: 1.0
If we subtract 51 from 86, we get 35.
Include the next digit (4) from the dividend after 35, then repeat: 354 / 51

Moving on to step 3:
If we divide 354 by 51, we get 6 and a remainder of 48.
The next digit of our result is 6. 
Result so far: 16.0
If we take 306 away from 354, we end up with 48.
Grab the next digit (6) from the dividend, add it to 48, then carry on: 486 / 51

Moving on to step 4:
51 can be fit into 486 9 times, resulting in a remainder of 27.
The next digit of our result is 9. 
Result so far: 169.0
The remainder is 27 after subtracting 459 from 486.
Append the next digit (5) from the dividend to 27 and continue with: 275 / 51

On to step 5:
51 goes into 275 5 times with a remainder of 20.
Record the quotient 5 as the next digit in the result. 
Result so far: 1695.0
Subtracting 255 from 275 leaves us with 20.
Grab the next digit (1) from the dividend, add it to 20, then carry on: 201 / 51

Advancing to step 6:
The number 51 fits into 201 3 times, leaving a remainder of 48.
Put 3 as the next digit of the answer. 
Result so far: 16953.0
Subtract 153 from 201 to get 48.
Since there are no more digits in the dividend, we add a zero to the remainder making it 480, and continue the process.

Moving on to step 7:
If we divide 480 by 51, we get 9 and a remainder of 21.
The next digit of our result is 9. 
Result so far: 16953.9
The remainder is 21 after subtracting 459 from 480.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Let's proceed to step 8:
The number 51 fits into 210 4 times, leaving a remainder of 6.
The next digit of our result is 4. 
Result so far: 16953.94
If we subtract 204 from 210, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Moving on to step 9:
When dividing 60 by 51, we get 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 16953.941
Deduct 51 from 60 and we're left with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 10:
When dividing 90 by 51, we get 1 with a remainder of 39.
Use 1 as the next digit of our solution. 
Result so far: 16953.9411
If we take 51 away from 90, we end up with 39.
Since there are no more digits in the dividend, we add a zero to the remainder making it 390, and continue the process.

After the division, we end up with 16953.9411 and a remainder of 0.00039.