We look at the division of 53129561 by 15 
Our goal is to divide 53129561 by 15.

Going ahead to step 1:
When dividing 5 by 15, we get 0 with a remainder of 5.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Fetch the next digit (3) from the dividend, attach it to 5 and continue: 53 / 15

Moving on to step 2:
When dividing 53 by 15, we get 3 with a remainder of 8.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we take 45 away from 53, we end up with 8.
Include the next digit (1) from the dividend after 8, then repeat: 81 / 15

Going ahead to step 3:
The number 15 fits into 81 5 times, leaving a remainder of 6.
Write down 5 as next digit of the result. 
Result so far: 35.0
The remainder is 6 after subtracting 75 from 81.
Take the next digit (2) from the dividend and append it to 6, then repeat: 62 / 15

On to step 4:
15 can be fit into 62 4 times, resulting in a remainder of 2.
Put 4 as the next digit of the answer. 
Result so far: 354.0
If we take 60 away from 62, we end up with 2.
Grab the next digit (9) from the dividend, add it to 2, then carry on: 29 / 15

Moving on to step 5:
If we divide 29 by 15, we get 1 and a remainder of 14.
Write down 1 as next digit of the result. 
Result so far: 3541.0
Subtract 15 from 29 to get 14.
Grab the next digit (5) from the dividend, add it to 14, then carry on: 145 / 15

Advancing to step 6:
When dividing 145 by 15, we get 9 with a remainder of 10.
The next digit of our result is 9. 
Result so far: 35419.0
Subtracting 135 from 145 leaves us with 10.
Append the next digit (6) from the dividend to 10 and continue with: 106 / 15

Advancing to step 7:
The number 15 fits into 106 7 times, leaving a remainder of 1.
Write down 7 as next digit of the result. 
Result so far: 354197.0
If we take 105 away from 106, we end up with 1.
Fetch the next digit (1) from the dividend, attach it to 1 and continue: 11 / 15

Going ahead to step 8:
15 can be fit into 11 0 times, resulting in a remainder of 11.
Record the quotient 0 as the next digit in the result. 
Result so far: 3541970.0
Subtract 0 from 11 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Step 9:
When dividing 110 by 15, we get 7 with a remainder of 5.
Record the quotient 7 as the next digit in the result. 
Result so far: 3541970.7
Deduct 105 from 110 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Going ahead to step 10:
50 divided by 15 is 3 with a remainder of 5.
Put 3 as the next digit of the answer. 
Result so far: 3541970.73
If we subtract 45 from 50, we get 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Moving on to step 11:
15 can be fit into 50 3 times, resulting in a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 3541970.733
The remainder is 5 after subtracting 45 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

After the division, we end up with 3541970.733 and a remainder of 0.0005.