Let's divide 54091021 by 521
We want to figure out the number of times 54091021 can be divided by 521.

Step 1:
The number 521 fits into 5 0 times, leaving a remainder of 5.
The next digit of our result is 0. 
Result so far: 0.0
If we take 0 away from 5, we end up with 5.
Append the next digit (4) from the dividend to 5 and continue with: 54 / 521

Moving on to step 2:
521 goes into 54 0 times with a remainder of 54.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 54 after subtracting 0 from 54.
Fetch the next digit (0) from the dividend, attach it to 54 and continue: 540 / 521

Going ahead to step 3:
540 divided by 521 is 1 with a remainder of 19.
The number 1 becomes the next digit in our result. 
Result so far: 1.0
If we subtract 521 from 540, we get 19.
Include the next digit (9) from the dividend after 19, then repeat: 199 / 521

Step 4:
If we divide 199 by 521, we get 0 and a remainder of 199.
The number 0 becomes the next digit in our result. 
Result so far: 10.0
Deduct 0 from 199 and we're left with 199.
Append the next digit (1) from the dividend to 199 and continue with: 1991 / 521

Let's proceed to step 5:
1991 divided by 521 is 3 with a remainder of 428.
Put 3 as the next digit of the answer. 
Result so far: 103.0
If we take 1563 away from 1991, we end up with 428.
Fetch the next digit (0) from the dividend, attach it to 428 and continue: 4280 / 521

Going ahead to step 6:
521 goes into 4280 8 times with a remainder of 112.
The number 8 becomes the next digit in our result. 
Result so far: 1038.0
If we subtract 4168 from 4280, we get 112.
Grab the next digit (2) from the dividend, add it to 112, then carry on: 1122 / 521

Advancing to step 7:
When dividing 1122 by 521, we get 2 with a remainder of 80.
Write down 2 as next digit of the result. 
Result so far: 10382.0
The remainder is 80 after subtracting 1042 from 1122.
Include the next digit (1) from the dividend after 80, then repeat: 801 / 521

Going ahead to step 8:
801 divided by 521 is 1 with a remainder of 280.
Put 1 as the next digit of the answer. 
Result so far: 103821.0
Subtracting 521 from 801 leaves us with 280.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2800, and continue the process.

Step 9:
If we divide 2800 by 521, we get 5 and a remainder of 195.
Use 5 as the next digit of our solution. 
Result so far: 103821.5
If we take 2605 away from 2800, we end up with 195.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1950, and continue the process.

Advancing to step 10:
1950 divided by 521 is 3 with a remainder of 387.
Record the quotient 3 as the next digit in the result. 
Result so far: 103821.53
Subtract 1563 from 1950 to get 387.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3870, and continue the process.

Advancing to step 11:
521 goes into 3870 7 times with a remainder of 223.
Put 7 as the next digit of the answer. 
Result so far: 103821.537
If we take 3647 away from 3870, we end up with 223.
Since there are no more digits in the dividend, we add a zero to the remainder making it 2230, and continue the process.

Moving on to step 12:
The number 521 fits into 2230 4 times, leaving a remainder of 146.
The number 4 becomes the next digit in our result. 
Result so far: 103821.5374
If we take 2084 away from 2230, we end up with 146.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1460, and continue the process.

Let's proceed to step 13:
The number 521 fits into 1460 2 times, leaving a remainder of 418.
Put 2 as the next digit of the answer. 
Result so far: 103821.53742
Subtracting 1042 from 1460 leaves us with 418.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4180, and continue the process.

Moving on to step 14:
The number 521 fits into 4180 8 times, leaving a remainder of 12.
The next digit of our result is 8. 
Result so far: 103821.537428
Subtract 4168 from 4180 to get 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

On to step 15:
When dividing 120 by 521, we get 0 with a remainder of 120.
The number 0 becomes the next digit in our result. 
Result so far: 103821.537428
The remainder is 120 after subtracting 0 from 120.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1200, and continue the process.

Advancing to step 16:
1200 divided by 521 is 2 with a remainder of 158.
The number 2 becomes the next digit in our result. 
Result so far: 103821.53742802
Subtracting 1042 from 1200 leaves us with 158.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1580, and continue the process.

Our division results in 103821.53742802 with a remaining 1.58e-07.