161908 ÷ 21 
We want to figure out the number of times 161908 can be divided by 21.

Let's proceed to step 1:
21 goes into 1 0 times with a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Bring next digit (6) of the dividend behind the 1 and repeat the process: 16 / 21

Going ahead to step 2:
The number 21 fits into 16 0 times, leaving a remainder of 16.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtract 0 from 16 to get 16.
Take the next digit (1) from the dividend and append it to 16, then repeat: 161 / 21

Going ahead to step 3:
When dividing 161 by 21, we get 7 with a remainder of 14.
The next digit of our result is 7. 
Result so far: 7.0
If we take 147 away from 161, we end up with 14.
Append the next digit (9) from the dividend to 14 and continue with: 149 / 21

On to step 4:
If we divide 149 by 21, we get 7 and a remainder of 2.
The number 7 becomes the next digit in our result. 
Result so far: 77.0
Deduct 147 from 149 and we're left with 2.
Include the next digit (0) from the dividend after 2, then repeat: 20 / 21

Advancing to step 5:
If we divide 20 by 21, we get 0 and a remainder of 20.
The number 0 becomes the next digit in our result. 
Result so far: 770.0
If we subtract 0 from 20, we get 20.
Append the next digit (8) from the dividend to 20 and continue with: 208 / 21

Moving on to step 6:
The number 21 fits into 208 9 times, leaving a remainder of 19.
Record the quotient 9 as the next digit in the result. 
Result so far: 7709.0
Subtract 189 from 208 to 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.

Going ahead to step 7:
The number 21 fits into 190 9 times, leaving a remainder of 1.
The next digit of our result is 9. 
Result so far: 7709.9
If we take 189 away from 190, we end up with 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Advancing to step 8:
21 goes into 10 0 times with a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 7709.9
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

On to step 9:
The number 21 fits into 100 4 times, leaving a remainder of 16.
Use 4 as the next digit of our solution. 
Result so far: 7709.904
Subtract 84 from 100 to get 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 10:
21 can be fit into 160 7 times, resulting in a remainder of 13.
The next digit of our result is 7. 
Result so far: 7709.9047
If we take 147 away from 160, we end up with 13.
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 11:
130 divided by 21 is 6 with a remainder of 4.
Write down 6 as next digit of the result. 
Result so far: 7709.90476
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.

On to step 12:
21 can be fit into 40 1 times, resulting in a remainder of 19.
Write down 1 as next digit of the result. 
Result so far: 7709.904761
The remainder is 19 after subtracting 21 from 40.
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 13:
21 can be fit into 190 9 times, resulting in a remainder of 1.
The number 9 becomes the next digit in our result. 
Result so far: 7709.9047619
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.

On to step 14:
If we divide 10 by 21, we get 0 and a remainder of 10.
The number 0 becomes the next digit in our result. 
Result so far: 7709.9047619
If we take 0 away from 10, we end up with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

The quotient of the division is 7709.9047619, and the remainder is 1e-08.