66621293 ÷ 853 
Our goal is to divide 66621293 by 853.

Let's proceed to step 1:
When dividing 6 by 853, we get 0 with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Append the next digit (6) from the dividend to 6 and continue with: 66 / 853

On to step 2:
66 divided by 853 is 0 with a remainder of 66.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 66 after subtracting 0 from 66.
Fetch the next digit (6) from the dividend, attach it to 66 and continue: 666 / 853

Moving on to step 3:
666 divided by 853 is 0 with a remainder of 666.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 666 leaves us with 666.
Bring next digit (2) of the dividend behind the 666 and repeat the process: 6662 / 853

Step 4:
853 can be fit into 6662 7 times, resulting in a remainder of 691.
The next digit of our result is 7. 
Result so far: 7.0
If we take 5971 away from 6662, we end up with 691.
Grab the next digit (1) from the dividend, add it to 691, then carry on: 6911 / 853

Step 5:
6911 divided by 853 is 8 with a remainder of 87.
Use 8 as the next digit of our solution. 
Result so far: 78.0
If we take 6824 away from 6911, we end up with 87.
Grab the next digit (2) from the dividend, add it to 87, then carry on: 872 / 853

On to step 6:
853 can be fit into 872 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 781.0
Subtracting 853 from 872 leaves us with 19.
Include the next digit (9) from the dividend after 19, then repeat: 199 / 853

Advancing to step 7:
199 divided by 853 is 0 with a remainder of 199.
Record the quotient 0 as the next digit in the result. 
Result so far: 7810.0
Subtracting 0 from 199 leaves us with 199.
Bring next digit (3) of the dividend behind the 199 and repeat the process: 1993 / 853

Let's proceed to step 8:
The number 853 fits into 1993 2 times, leaving a remainder of 287.
Use 2 as the next digit of our solution. 
Result so far: 78102.0
Deduct 1706 from 1993 and we're left with 287.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2870, and continue the process.

Moving on to step 9:
When dividing 2870 by 853, we get 3 with a remainder of 311.
The number 3 becomes the next digit in our result. 
Result so far: 78102.3
If we take 2559 away from 2870, we end up with 311.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3110, and continue the process.

Advancing to step 10:
3110 divided by 853 is 3 with a remainder of 551.
Write down 3 as next digit of the result. 
Result so far: 78102.33
If we subtract 2559 from 3110, we get 551.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5510, and continue the process.

After the division, we end up with 78102.33 and a remainder of 0.551.