61551906 ÷ 645 
We want to divide 61551906 by 645.

Going ahead to step 1:
6 divided by 645 is 0 with a remainder of 6.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 6 after subtracting 0 from 6.
Include the next digit (1) from the dividend after 6, then repeat: 61 / 645

Step 2:
If we divide 61 by 645, we get 0 and a remainder of 61.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 61, we get 61.
Bring next digit (5) of the dividend behind the 61 and repeat the process: 615 / 645

Going ahead to step 3:
When dividing 615 by 645, we get 0 with a remainder of 615.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 615, we end up with 615.
Append the next digit (5) from the dividend to 615 and continue with: 6155 / 645

On to step 4:
6155 divided by 645 is 9 with a remainder of 350.
Use 9 as the next digit of our solution. 
Result so far: 9.0
If we take 5805 away from 6155, we end up with 350.
Fetch the next digit (1) from the dividend, attach it to 350 and continue: 3501 / 645

Step 5:
The number 645 fits into 3501 5 times, leaving a remainder of 276.
Record the quotient 5 as the next digit in the result. 
Result so far: 95.0
If we subtract 3225 from 3501, we get 276.
Bring next digit (9) of the dividend behind the 276 and repeat the process: 2769 / 645

Step 6:
When dividing 2769 by 645, we get 4 with a remainder of 189.
Put 4 as the next digit of the answer. 
Result so far: 954.0
If we take 2580 away from 2769, we end up with 189.
Include the next digit (0) from the dividend after 189, then repeat: 1890 / 645

Moving on to step 7:
645 can be fit into 1890 2 times, resulting in a remainder of 600.
Use 2 as the next digit of our solution. 
Result so far: 9542.0
Deduct 1290 from 1890 and we're left with 600.
Include the next digit (6) from the dividend after 600, then repeat: 6006 / 645

Let's proceed to step 8:
645 goes into 6006 9 times with a remainder of 201.
The next digit of our result is 9. 
Result so far: 95429.0
The remainder is 201 after subtracting 5805 from 6006.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2010, and continue the process.

On to step 9:
The number 645 fits into 2010 3 times, leaving a remainder of 75.
The next digit of our result is 3. 
Result so far: 95429.3
If we subtract 1935 from 2010, we get 75.
Since there are no more digits in the dividend, we add a zero to the remainder making it 750, and continue the process.

Step 10:
The number 645 fits into 750 1 times, leaving a remainder of 105.
The next digit of our result is 1. 
Result so far: 95429.31
If we take 645 away from 750, we end up with 105.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1050, and continue the process.

On to step 11:
645 goes into 1050 1 times with a remainder of 405.
Put 1 as the next digit of the answer. 
Result so far: 95429.311
Subtracting 645 from 1050 leaves us with 405.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4050, and continue the process.

The quotient of the division is 95429.311, and the remainder is 0.0405.