21931 ÷ 30 
We're looking to find how many times 30 goes into 21931.

Going ahead to step 1:
2 divided by 30 is 0 with a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
The remainder is 2 after subtracting 0 from 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 30

Let's proceed to step 2:
21 divided by 30 is 0 with a remainder of 21.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtract 0 from 21 to get 21.
Take the next digit (9) from the dividend and append it to 21, then repeat: 219 / 30

Moving on to step 3:
When dividing 219 by 30, we get 7 with a remainder of 9.
Put 7 as the next digit of the answer. 
Result so far: 7.0
The remainder is 9 after subtracting 210 from 219.
Bring next digit (3) of the dividend behind the 9 and repeat the process: 93 / 30

Moving on to step 4:
If we divide 93 by 30, we get 3 and a remainder of 3.
Use 3 as the next digit of our solution. 
Result so far: 73.0
If we subtract 90 from 93, we get 3.
Include the next digit (1) from the dividend after 3, then repeat: 31 / 30

Going ahead to step 5:
31 divided by 30 is 1 with a remainder of 1.
Record the quotient 1 as the next digit in the result. 
Result so far: 731.0
If we take 30 away from 31, 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.

On to step 6:
10 divided by 30 is 0 with a remainder of 10.
The next digit of our result is 0. 
Result so far: 731.0
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.

Let's proceed to step 7:
The number 30 fits into 100 3 times, leaving a remainder of 10.
The next digit of our result is 3. 
Result so far: 731.03
Subtract 90 from 100 to 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.

Going ahead to step 8:
30 can be fit into 100 3 times, resulting in a remainder of 10.
Record the quotient 3 as the next digit in the result. 
Result so far: 731.033
If we subtract 90 from 100, 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.

The final result is 731.033 with a remainder of 0.001.