21212908 ÷ 39 
Our goal is to divide 21212908 by 39.

Moving on to step 1:
The number 39 fits into 2 0 times, leaving a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 39

Going ahead to step 2:
If we divide 21 by 39, we get 0 and 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 (2) from the dividend and append it to 21, then repeat: 212 / 39

Advancing to step 3:
39 can be fit into 212 5 times, resulting in a remainder of 17.
Write down 5 as next digit of the result. 
Result so far: 5.0
Deduct 195 from 212 and we're left with 17.
Include the next digit (1) from the dividend after 17, then repeat: 171 / 39

Let's proceed to step 4:
171 divided by 39 is 4 with a remainder of 15.
The number 4 becomes the next digit in our result. 
Result so far: 54.0
If we subtract 156 from 171, we get 15.
Append the next digit (2) from the dividend to 15 and continue with: 152 / 39

Step 5:
The number 39 fits into 152 3 times, leaving a remainder of 35.
Use 3 as the next digit of our solution. 
Result so far: 543.0
Deduct 117 from 152 and we're left with 35.
Bring next digit (9) of the dividend behind the 35 and repeat the process: 359 / 39

Going ahead to step 6:
When dividing 359 by 39, we get 9 with a remainder of 8.
Write down 9 as next digit of the result. 
Result so far: 5439.0
Subtract 351 from 359 to get 8.
Append the next digit (0) from the dividend to 8 and continue with: 80 / 39

On to step 7:
When dividing 80 by 39, we get 2 with a remainder of 2.
Use 2 as the next digit of our solution. 
Result so far: 54392.0
Deduct 78 from 80 and we're left with 2.
Append the next digit (8) from the dividend to 2 and continue with: 28 / 39

Going ahead to step 8:
28 divided by 39 is 0 with a remainder of 28.
The next digit of our result is 0. 
Result so far: 543920.0
Deduct 0 from 28 and we're left with 28.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

Moving on to step 9:
If we divide 280 by 39, we get 7 and a remainder of 7.
The number 7 becomes the next digit in our result. 
Result so far: 543920.7
If we subtract 273 from 280, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

On to step 10:
39 can be fit into 70 1 times, resulting in a remainder of 31.
The number 1 becomes the next digit in our result. 
Result so far: 543920.71
The remainder is 31 after subtracting 39 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

Step 11:
If we divide 310 by 39, we get 7 and a remainder of 37.
The next digit of our result is 7. 
Result so far: 543920.717
Subtracting 273 from 310 leaves us with 37.
Since there are no more digits in the dividend, we add a zero to the remainder making it 370, and continue the process.

Let's proceed to step 12:
39 can be fit into 370 9 times, resulting in a remainder of 19.
Use 9 as the next digit of our solution. 
Result so far: 543920.7179
Subtract 351 from 370 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.

Let's proceed to step 13:
39 goes into 190 4 times with a remainder of 34.
Put 4 as the next digit of the answer. 
Result so far: 543920.71794
Subtracting 156 from 190 leaves us with 34.
Since there are no more digits in the dividend, we add a zero to the remainder making it 340, and continue the process.

Moving on to step 14:
If we divide 340 by 39, we get 8 and a remainder of 28.
The number 8 becomes the next digit in our result. 
Result so far: 543920.717948
The remainder is 28 after subtracting 312 from 340.
Since there are no more digits in the dividend, we add a zero to the remainder making it 280, and continue the process.

On to step 15:
280 divided by 39 is 7 with a remainder of 7.
Use 7 as the next digit of our solution. 
Result so far: 543920.7179487
Subtract 273 from 280 to get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Advancing to step 16:
The number 39 fits into 70 1 times, leaving a remainder of 31.
Put 1 as the next digit of the answer. 
Result so far: 543920.71794871
Deduct 39 from 70 and we're left with 31.
Since there are no more digits in the dividend, we add a zero to the remainder making it 310, and continue the process.

In conclusion, the division gives 543920.71794871 with a balance of 3.1e-08.