666842 ÷ 21 
We want to figure out the number of times 666842 can be divided by 21.

Let's proceed to step 1:
21 goes into 6 0 times with a remainder of 6.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 6, we get 6.
Grab the next digit (6) from the dividend, add it to 6, then carry on: 66 / 21

Advancing to step 2:
The number 21 fits into 66 3 times, leaving a remainder of 3.
Put 3 as the next digit of the answer. 
Result so far: 3.0
Subtract 63 from 66 to get 3.
Include the next digit (6) from the dividend after 3, then repeat: 36 / 21

Advancing to step 3:
21 goes into 36 1 times with a remainder of 15.
The next digit of our result is 1. 
Result so far: 31.0
If we subtract 21 from 36, we get 15.
Bring next digit (8) of the dividend behind the 15 and repeat the process: 158 / 21

Step 4:
If we divide 158 by 21, we get 7 and a remainder of 11.
The number 7 becomes the next digit in our result. 
Result so far: 317.0
If we take 147 away from 158, we end up with 11.
Take the next digit (4) from the dividend and append it to 11, then repeat: 114 / 21

Advancing to step 5:
21 goes into 114 5 times with a remainder of 9.
Write down 5 as next digit of the result. 
Result so far: 3175.0
Subtract 105 from 114 to get 9.
Append the next digit (2) from the dividend to 9 and continue with: 92 / 21

On to step 6:
When dividing 92 by 21, we get 4 with a remainder of 8.
Record the quotient 4 as the next digit in the result. 
Result so far: 31754.0
If we subtract 84 from 92, we get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Moving on to step 7:
The number 21 fits into 80 3 times, leaving a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 31754.3
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 8:
The number 21 fits into 170 8 times, leaving a remainder of 2.
Write down 8 as next digit of the result. 
Result so far: 31754.38
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

On to step 9:
21 can be fit into 20 0 times, resulting in a remainder of 20.
Put 0 as the next digit of the answer. 
Result so far: 31754.38
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 10:
21 goes into 200 9 times with a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 31754.3809
Deduct 189 from 200 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Going ahead to step 11:
When dividing 110 by 21, we get 5 with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 31754.38095
Deduct 105 from 110 and we're left with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 12:
When dividing 50 by 21, we get 2 with a remainder of 8.
Record the quotient 2 as the next digit in the result. 
Result so far: 31754.380952
Deduct 42 from 50 and we're left with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

On to step 13:
80 divided by 21 is 3 with a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 31754.3809523
Subtract 63 from 80 to get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Going ahead to step 14:
170 divided by 21 is 8 with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 31754.38095238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

The quotient of the division is 31754.38095238, and the remainder is 2e-09.