810123 ÷ 51 
We want to divide 810123 by 51.

Let's proceed to step 1:
51 goes into 8 0 times with a remainder of 8.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Bring next digit (1) of the dividend behind the 8 and repeat the process: 81 / 51

Going ahead to step 2:
81 divided by 51 is 1 with a remainder of 30.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
Subtract 51 from 81 to get 30.
Include the next digit (0) from the dividend after 30, then repeat: 300 / 51

On to step 3:
The number 51 fits into 300 5 times, leaving a remainder of 45.
Use 5 as the next digit of our solution. 
Result so far: 15.0
Subtracting 255 from 300 leaves us with 45.
Take the next digit (1) from the dividend and append it to 45, then repeat: 451 / 51

Step 4:
51 can be fit into 451 8 times, resulting in a remainder of 43.
Put 8 as the next digit of the answer. 
Result so far: 158.0
Subtract 408 from 451 to get 43.
Bring next digit (2) of the dividend behind the 43 and repeat the process: 432 / 51

Step 5:
432 divided by 51 is 8 with a remainder of 24.
Write down 8 as next digit of the result. 
Result so far: 1588.0
Deduct 408 from 432 and we're left with 24.
Append the next digit (3) from the dividend to 24 and continue with: 243 / 51

Let's proceed to step 6:
243 divided by 51 is 4 with a remainder of 39.
Record the quotient 4 as the next digit in the result. 
Result so far: 15884.0
If we take 204 away from 243, 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.

Moving on to step 7:
390 divided by 51 is 7 with a remainder of 33.
The next digit of our result is 7. 
Result so far: 15884.7
Subtracting 357 from 390 leaves us with 33.
Since there are no more digits in the dividend, we add a zero to the remainder making it 330, and continue the process.

Going ahead to step 8:
If we divide 330 by 51, we get 6 and a remainder of 24.
Write down 6 as next digit of the result. 
Result so far: 15884.76
If we take 306 away from 330, we end up with 24.
Since there are no more digits in the dividend, we add a zero to the remainder making it 240, and continue the process.

Let's proceed to step 9:
240 divided by 51 is 4 with a remainder of 36.
Put 4 as the next digit of the answer. 
Result so far: 15884.764
Subtracting 204 from 240 leaves us with 36.
Since there are no more digits in the dividend, we add a zero to the remainder making it 360, and continue the process.

On to step 10:
The number 51 fits into 360 7 times, leaving a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 15884.7647
Subtract 357 from 360 to get 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

On to step 11:
51 can be fit into 30 0 times, resulting in a remainder of 30.
Write down 0 as next digit of the result. 
Result so far: 15884.7647
Subtract 0 from 30 to get 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 300, and continue the process.

Going ahead to step 12:
The number 51 fits into 300 5 times, leaving a remainder of 45.
Write down 5 as next digit of the result. 
Result so far: 15884.764705
Subtract 255 from 300 to get 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 450, and continue the process.

Going ahead to step 13:
51 can be fit into 450 8 times, resulting in a remainder of 42.
Put 8 as the next digit of the answer. 
Result so far: 15884.7647058
The remainder is 42 after subtracting 408 from 450.
Since there are no more digits in the dividend, we add a zero to the remainder making it 420, and continue the process.

Advancing to step 14:
51 goes into 420 8 times with a remainder of 12.
Record the quotient 8 as the next digit in the result. 
Result so far: 15884.76470588
Subtracting 408 from 420 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final outcome is 15884.76470588, with a leftover of 1.2e-08.