661108 ÷ 21 
We want to figure out the number of times 661108 can be divided by 21.

Step 1:
If we divide 6 by 21, we get 0 and 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.
Fetch the next digit (6) from the dividend, attach it to 6 and continue: 66 / 21

On to step 2:
21 can be fit into 66 3 times, resulting in a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 3.0
If we take 63 away from 66, we end up with 3.
Fetch the next digit (1) from the dividend, attach it to 3 and continue: 31 / 21

On to step 3:
The number 21 fits into 31 1 times, leaving a remainder of 10.
Put 1 as the next digit of the answer. 
Result so far: 31.0
Deduct 21 from 31 and we're left with 10.
Bring next digit (1) of the dividend behind the 10 and repeat the process: 101 / 21

Step 4:
21 goes into 101 4 times with a remainder of 17.
Record the quotient 4 as the next digit in the result. 
Result so far: 314.0
Subtracting 84 from 101 leaves us with 17.
Take the next digit (0) from the dividend and append it to 17, then repeat: 170 / 21

Going ahead to step 5:
When dividing 170 by 21, we get 8 with a remainder of 2.
Put 8 as the next digit of the answer. 
Result so far: 3148.0
Subtract 168 from 170 to get 2.
Grab the next digit (8) from the dividend, add it to 2, then carry on: 28 / 21

Step 6:
When dividing 28 by 21, we get 1 with a remainder of 7.
Use 1 as the next digit of our solution. 
Result so far: 31481.0
The remainder is 7 after subtracting 21 from 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Moving on to step 7:
When dividing 70 by 21, we get 3 with a remainder of 7.
Use 3 as the next digit of our solution. 
Result so far: 31481.3
If we subtract 63 from 70, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Step 8:
The number 21 fits into 70 3 times, leaving a remainder of 7.
The next digit of our result is 3. 
Result so far: 31481.33
Subtract 63 from 70 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

The final outcome is 31481.33, with a leftover of 0.007.