We're dividing 21293187 by 621 
We want to figure out the number of times 21293187 can be divided by 621.

Step 1:
621 can be fit into 2 0 times, resulting in a remainder of 2.
Write down 0 as next digit of the result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Grab the next digit (1) from the dividend, add it to 2, then carry on: 21 / 621

Let's proceed to step 2:
If we divide 21 by 621, we get 0 and a remainder of 21.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Take the next digit (2) from the dividend and append it to 21, then repeat: 212 / 621

On to step 3:
The number 621 fits into 212 0 times, leaving a remainder of 212.
The next digit of our result is 0. 
Result so far: 0.0
Subtracting 0 from 212 leaves us with 212.
Fetch the next digit (9) from the dividend, attach it to 212 and continue: 2129 / 621

Let's proceed to step 4:
621 goes into 2129 3 times with a remainder of 266.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Deduct 1863 from 2129 and we're left with 266.
Append the next digit (3) from the dividend to 266 and continue with: 2663 / 621

Moving on to step 5:
The number 621 fits into 2663 4 times, leaving a remainder of 179.
The next digit of our result is 4. 
Result so far: 34.0
If we subtract 2484 from 2663, we get 179.
Append the next digit (1) from the dividend to 179 and continue with: 1791 / 621

On to step 6:
The number 621 fits into 1791 2 times, leaving a remainder of 549.
Write down 2 as next digit of the result. 
Result so far: 342.0
The remainder is 549 after subtracting 1242 from 1791.
Append the next digit (8) from the dividend to 549 and continue with: 5498 / 621

Let's proceed to step 7:
The number 621 fits into 5498 8 times, leaving a remainder of 530.
Put 8 as the next digit of the answer. 
Result so far: 3428.0
The remainder is 530 after subtracting 4968 from 5498.
Take the next digit (7) from the dividend and append it to 530, then repeat: 5307 / 621

Let's proceed to step 8:
When dividing 5307 by 621, we get 8 with a remainder of 339.
Put 8 as the next digit of the answer. 
Result so far: 34288.0
If we take 4968 away from 5307, we end up with 339.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3390, and continue the process.

Advancing to step 9:
621 goes into 3390 5 times with a remainder of 285.
Record the quotient 5 as the next digit in the result. 
Result so far: 34288.5
If we subtract 3105 from 3390, we get 285.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2850, and continue the process.

Let's proceed to step 10:
When dividing 2850 by 621, we get 4 with a remainder of 366.
The next digit of our result is 4. 
Result so far: 34288.54
Subtracting 2484 from 2850 leaves us with 366.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3660, and continue the process.

Moving on to step 11:
If we divide 3660 by 621, we get 5 and a remainder of 555.
Write down 5 as next digit of the result. 
Result so far: 34288.545
Subtract 3105 from 3660 to get 555.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5550, and continue the process.

Step 12:
5550 divided by 621 is 8 with a remainder of 582.
Record the quotient 8 as the next digit in the result. 
Result so far: 34288.5458
If we take 4968 away from 5550, we end up with 582.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5820, and continue the process.

Advancing to step 13:
621 can be fit into 5820 9 times, resulting in a remainder of 231.
Write down 9 as next digit of the result. 
Result so far: 34288.54589
Deduct 5589 from 5820 and we're left with 231.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2310, and continue the process.

On to step 14:
621 can be fit into 2310 3 times, resulting in a remainder of 447.
The number 3 becomes the next digit in our result. 
Result so far: 34288.545893
Subtract 1863 from 2310 to get 447.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4470, and continue the process.

Let's proceed to step 15:
When dividing 4470 by 621, we get 7 with a remainder of 123.
The number 7 becomes the next digit in our result. 
Result so far: 34288.5458937
If we subtract 4347 from 4470, we get 123.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1230, and continue the process.

Going ahead to step 16:
When dividing 1230 by 621, we get 1 with a remainder of 609.
The number 1 becomes the next digit in our result. 
Result so far: 34288.54589371
Subtracting 621 from 1230 leaves us with 609.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6090, and continue the process.

The quotient of the division is 34288.54589371, and the remainder is 6.09e-07.