53158163 ÷ 865 
We want to figure out the number of times 53158163 can be divided by 865.

Let's proceed to step 1:
The number 865 fits into 5 0 times, leaving a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 5, we get 5.
Include the next digit (3) from the dividend after 5, then repeat: 53 / 865

Going ahead to step 2:
53 divided by 865 is 0 with a remainder of 53.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Deduct 0 from 53 and we're left with 53.
Append the next digit (1) from the dividend to 53 and continue with: 531 / 865

Step 3:
If we divide 531 by 865, we get 0 and a remainder of 531.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 531, we get 531.
Grab the next digit (5) from the dividend, add it to 531, then carry on: 5315 / 865

Going ahead to step 4:
865 can be fit into 5315 6 times, resulting in a remainder of 125.
The next digit of our result is 6. 
Result so far: 6.0
If we take 5190 away from 5315, we end up with 125.
Bring next digit (8) of the dividend behind the 125 and repeat the process: 1258 / 865

Advancing to step 5:
The number 865 fits into 1258 1 times, leaving a remainder of 393.
Write down 1 as next digit of the result. 
Result so far: 61.0
Deduct 865 from 1258 and we're left with 393.
Append the next digit (1) from the dividend to 393 and continue with: 3931 / 865

Going ahead to step 6:
When dividing 3931 by 865, we get 4 with a remainder of 471.
The next digit of our result is 4. 
Result so far: 614.0
If we take 3460 away from 3931, we end up with 471.
Append the next digit (6) from the dividend to 471 and continue with: 4716 / 865

Step 7:
When dividing 4716 by 865, we get 5 with a remainder of 391.
Write down 5 as next digit of the result. 
Result so far: 6145.0
Deduct 4325 from 4716 and we're left with 391.
Bring next digit (3) of the dividend behind the 391 and repeat the process: 3913 / 865

Going ahead to step 8:
3913 divided by 865 is 4 with a remainder of 453.
Put 4 as the next digit of the answer. 
Result so far: 61454.0
If we take 3460 away from 3913, we end up with 453.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4530, and continue the process.

Advancing to step 9:
When dividing 4530 by 865, we get 5 with a remainder of 205.
Write down 5 as next digit of the result. 
Result so far: 61454.5
Subtracting 4325 from 4530 leaves us with 205.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2050, and continue the process.

Moving on to step 10:
If we divide 2050 by 865, we get 2 and a remainder of 320.
Record the quotient 2 as the next digit in the result. 
Result so far: 61454.52
If we subtract 1730 from 2050, we get 320.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3200, and continue the process.

Let's proceed to step 11:
865 goes into 3200 3 times with a remainder of 605.
Use 3 as the next digit of our solution. 
Result so far: 61454.523
If we subtract 2595 from 3200, we get 605.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6050, and continue the process.

Advancing to step 12:
The number 865 fits into 6050 6 times, leaving a remainder of 860.
Record the quotient 6 as the next digit in the result. 
Result so far: 61454.5236
Subtract 5190 from 6050 to get 860.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8600, and continue the process.

Advancing to step 13:
8600 divided by 865 is 9 with a remainder of 815.
Write down 9 as next digit of the result. 
Result so far: 61454.52369
If we take 7785 away from 8600, we end up with 815.
Since there are no more digits in the dividend, we add a zero to the remainder making it 8150, and continue the process.

On to step 14:
When dividing 8150 by 865, we get 9 with a remainder of 365.
Use 9 as the next digit of our solution. 
Result so far: 61454.523699
If we subtract 7785 from 8150, we get 365.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3650, and continue the process.

The final outcome is 61454.523699, with a leftover of 3.65e-05.