855121 ÷ 15 
Our goal is to divide 855121 by 15.

Moving on to step 1:
15 can be fit into 8 0 times, resulting in a remainder of 8.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 8 after subtracting 0 from 8.
Grab the next digit (5) from the dividend, add it to 8, then carry on: 85 / 15

Advancing to step 2:
If we divide 85 by 15, we get 5 and a remainder of 10.
Use 5 as the next digit of our solution. 
Result so far: 5.0
If we subtract 75 from 85, we get 10.
Take the next digit (5) from the dividend and append it to 10, then repeat: 105 / 15

Step 3:
The number 15 fits into 105 7 times, leaving a remainder of 0.
Use 7 as the next digit of our solution. 
Result so far: 57.0
If we take 105 away from 105, we end up with 0.
Fetch the next digit (1) from the dividend, attach it to 0 and continue: 1 / 15

On to step 4:
When dividing 1 by 15, we get 0 with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 570.0
If we take 0 away from 1, we end up with 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 15

Advancing to step 5:
The number 15 fits into 12 0 times, leaving a remainder of 12.
The number 0 becomes the next digit in our result. 
Result so far: 5700.0
Subtract 0 from 12 to get 12.
Grab the next digit (1) from the dividend, add it to 12, then carry on: 121 / 15

Advancing to step 6:
15 goes into 121 8 times with a remainder of 1.
Record the quotient 8 as the next digit in the result. 
Result so far: 57008.0
Subtracting 120 from 121 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.

Let's proceed to step 7:
15 goes into 10 0 times with a remainder of 10.
Record the quotient 0 as the next digit in the result. 
Result so far: 57008.0
Deduct 0 from 10 and we're left 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.

Advancing to step 8:
When dividing 100 by 15, we get 6 with a remainder of 10.
Put 6 as the next digit of the answer. 
Result so far: 57008.06
Deduct 90 from 100 and we're left 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.

Moving on to step 9:
When dividing 100 by 15, we get 6 with a remainder of 10.
Write down 6 as next digit of the result. 
Result so far: 57008.066
If we take 90 away from 100, 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.

After the division, we end up with 57008.066 and a remainder of 0.001.