Let's divide 16521031 by 15
We want to divide 16521031 by 15.

Going ahead to step 1:
15 can be fit into 1 0 times, resulting in a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Append the next digit (6) from the dividend to 1 and continue with: 16 / 15

Step 2:
When dividing 16 by 15, we get 1 with a remainder of 1.
Use 1 as the next digit of our solution. 
Result so far: 1.0
If we subtract 15 from 16, we get 1.
Grab the next digit (5) from the dividend, add it to 1, then carry on: 15 / 15

Step 3:
15 can be fit into 15 1 times, resulting in a remainder of 0.
The next digit of our result is 1. 
Result so far: 11.0
If we take 15 away from 15, we end up with 0.
Take the next digit (2) from the dividend and append it to 0, then repeat: 2 / 15

Let's proceed to step 4:
2 divided by 15 is 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 110.0
Subtract 0 from 2 to get 2.
Bring next digit (1) of the dividend behind the 2 and repeat the process: 21 / 15

On to step 5:
15 can be fit into 21 1 times, resulting in a remainder of 6.
Write down 1 as next digit of the result. 
Result so far: 1101.0
If we take 15 away from 21, we end up with 6.
Include the next digit (0) from the dividend after 6, then repeat: 60 / 15

Moving on to step 6:
60 divided by 15 is 4 with a remainder of 0.
The next digit of our result is 4. 
Result so far: 11014.0
If we take 60 away from 60, we end up with 0.
Append the next digit (3) from the dividend to 0 and continue with: 3 / 15

Let's proceed to step 7:
15 goes into 3 0 times with a remainder of 3.
Put 0 as the next digit of the answer. 
Result so far: 110140.0
Deduct 0 from 3 and we're left with 3.
Append the next digit (1) from the dividend to 3 and continue with: 31 / 15

On to step 8:
31 divided by 15 is 2 with a remainder of 1.
Write down 2 as next digit of the result. 
Result so far: 1101402.0
Subtracting 30 from 31 leaves us with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 9:
If we divide 10 by 15, we get 0 and a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 1101402.0
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Step 10:
The number 15 fits into 100 6 times, leaving a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 1101402.06
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Advancing to step 11:
15 can be fit into 100 6 times, resulting in a remainder of 10.
Record the quotient 6 as the next digit in the result. 
Result so far: 1101402.066
The remainder is 10 after subtracting 90 from 100.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The quotient of the division is 1101402.066, and the remainder is 0.001.