We're dividing 168646 by 21 
We want to divide 168646 by 21.

Going ahead to step 1:
If we divide 1 by 21, we get 0 and a remainder of 1.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 1 after subtracting 0 from 1.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 21

Moving on to step 2:
The number 21 fits into 16 0 times, leaving a remainder of 16.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtract 0 from 16 to get 16.
Fetch the next digit (8) from the dividend, attach it to 16 and continue: 168 / 21

Advancing to step 3:
168 divided by 21 is 8 with a remainder of 0.
The next digit of our result is 8. 
Result so far: 8.0
Subtract 168 from 168 to get 0.
Include the next digit (6) from the dividend after 0, then repeat: 6 / 21

Step 4:
6 divided by 21 is 0 with a remainder of 6.
Write down 0 as next digit of the result. 
Result so far: 80.0
If we subtract 0 from 6, we get 6.
Grab the next digit (4) from the dividend, add it to 6, then carry on: 64 / 21

Going ahead to step 5:
When dividing 64 by 21, we get 3 with a remainder of 1.
Use 3 as the next digit of our solution. 
Result so far: 803.0
The remainder is 1 after subtracting 63 from 64.
Fetch the next digit (6) from the dividend, attach it to 1 and continue: 16 / 21

Step 6:
The number 21 fits into 16 0 times, leaving a remainder of 16.
The number 0 becomes the next digit in our result. 
Result so far: 8030.0
If we take 0 away from 16, we end up with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Let's proceed to step 7:
When dividing 160 by 21, we get 7 with a remainder of 13.
The number 7 becomes the next digit in our result. 
Result so far: 8030.7
The remainder is 13 after subtracting 147 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Moving on to step 8:
21 can be fit into 130 6 times, resulting in a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 8030.76
If we take 126 away from 130, we end up with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Step 9:
40 divided by 21 is 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 8030.761
If we subtract 21 from 40, we get 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

On to step 10:
If we divide 190 by 21, we get 9 and a remainder of 1.
Put 9 as the next digit of the answer. 
Result so far: 8030.7619
If we subtract 189 from 190, we get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Moving on to step 11:
When dividing 10 by 21, we get 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 8030.7619
If we subtract 0 from 10, we get 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Moving on to step 12:
When dividing 100 by 21, we get 4 with a remainder of 16.
The next digit of our result is 4. 
Result so far: 8030.761904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Moving on to step 13:
160 divided by 21 is 7 with a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 8030.7619047
If we subtract 147 from 160, we get 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 14:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 8030.76190476
Subtract 126 from 130 to get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final result is 8030.76190476 with a remainder of 4e-09.