Let's divide 51215574 by 865
Let's see how many times 865 fits into 51215574.

On to step 1:
The number 865 fits into 5 0 times, leaving a remainder of 5.
Write down 0 as next digit of the result. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Grab the next digit (1) from the dividend, add it to 5, then carry on: 51 / 865

On to step 2:
865 can be fit into 51 0 times, resulting in a remainder of 51.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 51 to get 51.
Append the next digit (2) from the dividend to 51 and continue with: 512 / 865

Going ahead to step 3:
If we divide 512 by 865, we get 0 and a remainder of 512.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 512, we end up with 512.
Take the next digit (1) from the dividend and append it to 512, then repeat: 5121 / 865

Advancing to step 4:
5121 divided by 865 is 5 with a remainder of 796.
Record the quotient 5 as the next digit in the result. 
Result so far: 5.0
If we subtract 4325 from 5121, we get 796.
Take the next digit (5) from the dividend and append it to 796, then repeat: 7965 / 865

Let's proceed to step 5:
When dividing 7965 by 865, we get 9 with a remainder of 180.
Put 9 as the next digit of the answer. 
Result so far: 59.0
Subtract 7785 from 7965 to get 180.
Include the next digit (5) from the dividend after 180, then repeat: 1805 / 865

Moving on to step 6:
865 can be fit into 1805 2 times, resulting in a remainder of 75.
Write down 2 as next digit of the result. 
Result so far: 592.0
Subtract 1730 from 1805 to get 75.
Take the next digit (7) from the dividend and append it to 75, then repeat: 757 / 865

Advancing to step 7:
The number 865 fits into 757 0 times, leaving a remainder of 757.
The number 0 becomes the next digit in our result. 
Result so far: 5920.0
If we subtract 0 from 757, we get 757.
Include the next digit (4) from the dividend after 757, then repeat: 7574 / 865

Step 8:
865 goes into 7574 8 times with a remainder of 654.
Write down 8 as next digit of the result. 
Result so far: 59208.0
The remainder is 654 after subtracting 6920 from 7574.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6540, and continue the process.

Going ahead to step 9:
6540 divided by 865 is 7 with a remainder of 485.
Write down 7 as next digit of the result. 
Result so far: 59208.7
Subtract 6055 from 6540 to get 485.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4850, and continue the process.

Moving on to step 10:
865 goes into 4850 5 times with a remainder of 525.
Write down 5 as next digit of the result. 
Result so far: 59208.75
Subtracting 4325 from 4850 leaves us with 525.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5250, and continue the process.

Going ahead to step 11:
The number 865 fits into 5250 6 times, leaving a remainder of 60.
The number 6 becomes the next digit in our result. 
Result so far: 59208.756
If we subtract 5190 from 5250, we get 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 600, and continue the process.

Advancing to step 12:
865 goes into 600 0 times with a remainder of 600.
Record the quotient 0 as the next digit in the result. 
Result so far: 59208.756
If we subtract 0 from 600, we get 600.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6000, and continue the process.

Advancing to step 13:
If we divide 6000 by 865, we get 6 and a remainder of 810.
The number 6 becomes the next digit in our result. 
Result so far: 59208.75606
Subtract 5190 from 6000 to get 810.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8100, and continue the process.

Let's proceed to step 14:
865 can be fit into 8100 9 times, resulting in a remainder of 315.
Put 9 as the next digit of the answer. 
Result so far: 59208.756069
Subtracting 7785 from 8100 leaves us with 315.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3150, and continue the process.

On to step 15:
865 goes into 3150 3 times with a remainder of 555.
Use 3 as the next digit of our solution. 
Result so far: 59208.7560693
Deduct 2595 from 3150 and we're left with 555.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5550, and continue the process.

Step 16:
The number 865 fits into 5550 6 times, leaving a remainder of 360.
Use 6 as the next digit of our solution. 
Result so far: 59208.75606936
The remainder is 360 after subtracting 5190 from 5550.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3600, and continue the process.

The final outcome is 59208.75606936, with a leftover of 3.6e-07.