We're dividing 631398 by 51 
We're looking to find how many times 51 goes into 631398.

Going ahead to step 1:
If we divide 6 by 51, we get 0 and a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Bring next digit (3) of the dividend behind the 6 and repeat the process: 63 / 51

Step 2:
51 goes into 63 1 times with a remainder of 12.
The next digit of our result is 1. 
Result so far: 1.0
Deduct 51 from 63 and we're left with 12.
Bring next digit (1) of the dividend behind the 12 and repeat the process: 121 / 51

Step 3:
If we divide 121 by 51, we get 2 and a remainder of 19.
The next digit of our result is 2. 
Result so far: 12.0
If we subtract 102 from 121, we get 19.
Bring next digit (3) of the dividend behind the 19 and repeat the process: 193 / 51

Going ahead to step 4:
The number 51 fits into 193 3 times, leaving a remainder of 40.
The number 3 becomes the next digit in our result. 
Result so far: 123.0
Subtracting 153 from 193 leaves us with 40.
Include the next digit (9) from the dividend after 40, then repeat: 409 / 51

Going ahead to step 5:
The number 51 fits into 409 8 times, leaving a remainder of 1.
The next digit of our result is 8. 
Result so far: 1238.0
If we take 408 away from 409, we end up with 1.
Bring next digit (8) of the dividend behind the 1 and repeat the process: 18 / 51

On to step 6:
When dividing 18 by 51, we get 0 with a remainder of 18.
The next digit of our result is 0. 
Result so far: 12380.0
Subtracting 0 from 18 leaves us with 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 7:
51 goes into 180 3 times with a remainder of 27.
The number 3 becomes the next digit in our result. 
Result so far: 12380.3
Subtracting 153 from 180 leaves us with 27.
Since there are no more digits in the dividend, we add a zero to the remainder making it 270, and continue the process.

Advancing to step 8:
When dividing 270 by 51, we get 5 with a remainder of 15.
Record the quotient 5 as the next digit in the result. 
Result so far: 12380.35
Deduct 255 from 270 and we're left with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 9:
150 divided by 51 is 2 with a remainder of 48.
Use 2 as the next digit of our solution. 
Result so far: 12380.352
If we subtract 102 from 150, we 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.

Going ahead to step 10:
If we divide 480 by 51, we get 9 and a remainder of 21.
The number 9 becomes the next digit in our result. 
Result so far: 12380.3529
If we subtract 459 from 480, we get 21.
Since there are no more digits in the dividend, we add a zero to the remainder making it 210, and continue the process.

Advancing to step 11:
If we divide 210 by 51, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 12380.35294
Deduct 204 from 210 and we're left with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 12:
The number 51 fits into 60 1 times, leaving a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 12380.352941
If we take 51 away from 60, we end up 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.

Going ahead to step 13:
51 can be fit into 90 1 times, resulting in a remainder of 39.
Write down 1 as next digit of the result. 
Result so far: 12380.3529411
The remainder is 39 after subtracting 51 from 90.
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 12380.3529411 and a remainder of 3.9e-07.