We look at the division of 660597 by 21 
Our goal is to divide 660597 by 21.

Advancing to step 1:
The number 21 fits into 6 0 times, leaving a remainder of 6.
Use 0 as the next digit of our solution. 
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.
The next digit of our result is 3. 
Result so far: 3.0
The remainder is 3 after subtracting 63 from 66.
Take the next digit (0) from the dividend and append it to 3, then repeat: 30 / 21

Let's proceed to step 3:
21 can be fit into 30 1 times, resulting in a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 31.0
Subtracting 21 from 30 leaves us with 9.
Include the next digit (5) from the dividend after 9, then repeat: 95 / 21

Let's proceed to step 4:
When dividing 95 by 21, we get 4 with a remainder of 11.
Use 4 as the next digit of our solution. 
Result so far: 314.0
If we take 84 away from 95, we end up with 11.
Fetch the next digit (9) from the dividend, attach it to 11 and continue: 119 / 21

Let's proceed to step 5:
If we divide 119 by 21, we get 5 and a remainder of 14.
The number 5 becomes the next digit in our result. 
Result so far: 3145.0
Subtract 105 from 119 to get 14.
Include the next digit (7) from the dividend after 14, then repeat: 147 / 21

Let's proceed to step 6:
The number 21 fits into 147 7 times, leaving a remainder of 0.
Record the quotient 7 as the next digit in the result. 
Result so far: 31457.0
Subtract 147 from 147 to get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Going ahead to step 7:
21 goes into 0 0 times with a remainder of 0.
Write down 0 as next digit of the result. 
Result so far: 31457.0
Subtracting 0 from 0 leaves us with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Moving on to step 8:
When dividing 0 by 21, we get 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 31457.0
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 31457.0, and the remainder is 0.0.