30864390 divided by 621 
Our goal is to divide 30864390 by 621.

Going ahead to step 1:
When dividing 3 by 621, we get 0 with a remainder of 3.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 3, we end up with 3.
Bring next digit (0) of the dividend behind the 3 and repeat the process: 30 / 621

Let's proceed to step 2:
When dividing 30 by 621, we get 0 with a remainder of 30.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 30, we get 30.
Include the next digit (8) from the dividend after 30, then repeat: 308 / 621

On to step 3:
When dividing 308 by 621, we get 0 with a remainder of 308.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 308 after subtracting 0 from 308.
Append the next digit (6) from the dividend to 308 and continue with: 3086 / 621

Going ahead to step 4:
The number 621 fits into 3086 4 times, leaving a remainder of 602.
The number 4 becomes the next digit in our result. 
Result so far: 4.0
The remainder is 602 after subtracting 2484 from 3086.
Append the next digit (4) from the dividend to 602 and continue with: 6024 / 621

On to step 5:
The number 621 fits into 6024 9 times, leaving a remainder of 435.
The next digit of our result is 9. 
Result so far: 49.0
Subtracting 5589 from 6024 leaves us with 435.
Take the next digit (3) from the dividend and append it to 435, then repeat: 4353 / 621

Moving on to step 6:
621 goes into 4353 7 times with a remainder of 6.
Put 7 as the next digit of the answer. 
Result so far: 497.0
Deduct 4347 from 4353 and we're left with 6.
Grab the next digit (9) from the dividend, add it to 6, then carry on: 69 / 621

On to step 7:
When dividing 69 by 621, we get 0 with a remainder of 69.
Record the quotient 0 as the next digit in the result. 
Result so far: 4970.0
If we subtract 0 from 69, we get 69.
Grab the next digit (0) from the dividend, add it to 69, then carry on: 690 / 621

Step 8:
690 divided by 621 is 1 with a remainder of 69.
The next digit of our result is 1. 
Result so far: 49701.0
Subtracting 621 from 690 leaves us with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

On to step 9:
621 goes into 690 1 times with a remainder of 69.
Record the quotient 1 as the next digit in the result. 
Result so far: 49701.1
Deduct 621 from 690 and we're left with 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

Going ahead to step 10:
If we divide 690 by 621, we get 1 and a remainder of 69.
The number 1 becomes the next digit in our result. 
Result so far: 49701.11
If we subtract 621 from 690, we get 69.
Since there are no more digits in the dividend, we add a zero to the remainder making it 690, and continue the process.

The final outcome is 49701.11, with a leftover of 0.069.