840521 ÷ 66 
Our goal is to divide 840521 by 66.

Going ahead to step 1:
66 can be fit into 8 0 times, resulting in a remainder of 8.
Write down 0 as next digit of the result. 
Result so far: 0.0
If we take 0 away from 8, we end up with 8.
Take the next digit (4) from the dividend and append it to 8, then repeat: 84 / 66

On to step 2:
If we divide 84 by 66, we get 1 and a remainder of 18.
The next digit of our result is 1. 
Result so far: 1.0
If we take 66 away from 84, we end up with 18.
Grab the next digit (0) from the dividend, add it to 18, then carry on: 180 / 66

Going ahead to step 3:
66 can be fit into 180 2 times, resulting in a remainder of 48.
Put 2 as the next digit of the answer. 
Result so far: 12.0
If we subtract 132 from 180, we get 48.
Grab the next digit (5) from the dividend, add it to 48, then carry on: 485 / 66

Moving on to step 4:
The number 66 fits into 485 7 times, leaving a remainder of 23.
Put 7 as the next digit of the answer. 
Result so far: 127.0
If we subtract 462 from 485, we get 23.
Grab the next digit (2) from the dividend, add it to 23, then carry on: 232 / 66

Going ahead to step 5:
The number 66 fits into 232 3 times, leaving a remainder of 34.
The next digit of our result is 3. 
Result so far: 1273.0
If we subtract 198 from 232, we get 34.
Include the next digit (1) from the dividend after 34, then repeat: 341 / 66

Let's proceed to step 6:
341 divided by 66 is 5 with a remainder of 11.
The next digit of our result is 5. 
Result so far: 12735.0
If we subtract 330 from 341, we 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.

Let's proceed to step 7:
66 can be fit into 110 1 times, resulting in a remainder of 44.
Record the quotient 1 as the next digit in the result. 
Result so far: 12735.1
If we subtract 66 from 110, we get 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Advancing to step 8:
When dividing 440 by 66, we get 6 with a remainder of 44.
The number 6 becomes the next digit in our result. 
Result so far: 12735.16
Deduct 396 from 440 and we're left with 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Going ahead to step 9:
440 divided by 66 is 6 with a remainder of 44.
Record the quotient 6 as the next digit in the result. 
Result so far: 12735.166
Subtract 396 from 440 to get 44.
Since there are no more digits in the dividend, we add a zero to the remainder making it 440, and continue the process.

Our division results in 12735.166 with a remaining 0.0044.