We're dividing 53932455 by 21 
We want to figure out the number of times 53932455 can be divided by 21.

Let's proceed to step 1:
21 goes into 5 0 times with a remainder of 5.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
Subtract 0 from 5 to get 5.
Include the next digit (3) from the dividend after 5, then repeat: 53 / 21

On to step 2:
If we divide 53 by 21, we get 2 and a remainder of 11.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
The remainder is 11 after subtracting 42 from 53.
Append the next digit (9) from the dividend to 11 and continue with: 119 / 21

Advancing to step 3:
If we divide 119 by 21, we get 5 and a remainder of 14.
The number 5 becomes the next digit in our result. 
Result so far: 25.0
Subtract 105 from 119 to get 14.
Include the next digit (3) from the dividend after 14, then repeat: 143 / 21

Moving on to step 4:
21 goes into 143 6 times with a remainder of 17.
Use 6 as the next digit of our solution. 
Result so far: 256.0
Subtract 126 from 143 to get 17.
Take the next digit (2) from the dividend and append it to 17, then repeat: 172 / 21

On to step 5:
21 can be fit into 172 8 times, resulting in a remainder of 4.
Write down 8 as next digit of the result. 
Result so far: 2568.0
If we take 168 away from 172, we end up with 4.
Grab the next digit (4) from the dividend, add it to 4, then carry on: 44 / 21

Moving on to step 6:
The number 21 fits into 44 2 times, leaving a remainder of 2.
Use 2 as the next digit of our solution. 
Result so far: 25682.0
Deduct 42 from 44 and we're left with 2.
Bring next digit (5) of the dividend behind the 2 and repeat the process: 25 / 21

Let's proceed to step 7:
If we divide 25 by 21, we get 1 and a remainder of 4.
Record the quotient 1 as the next digit in the result. 
Result so far: 256821.0
If we take 21 away from 25, we end up with 4.
Bring next digit (5) of the dividend behind the 4 and repeat the process: 45 / 21

Step 8:
45 divided by 21 is 2 with a remainder of 3.
The number 2 becomes the next digit in our result. 
Result so far: 2568212.0
The remainder is 3 after subtracting 42 from 45.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 9:
30 divided by 21 is 1 with a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 2568212.1
If we subtract 21 from 30, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 10:
If we divide 90 by 21, we get 4 and a remainder of 6.
The number 4 becomes the next digit in our result. 
Result so far: 2568212.14
If we subtract 84 from 90, we get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 11:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 2568212.142
The remainder is 18 after subtracting 42 from 60.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Advancing to step 12:
If we divide 180 by 21, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 2568212.1428
Subtract 168 from 180 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.

Step 13:
If we divide 120 by 21, we get 5 and a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 2568212.14285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Going ahead to step 14:
When dividing 150 by 21, we get 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 2568212.142857
The remainder is 3 after subtracting 147 from 150.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Let's proceed to step 15:
If we divide 30 by 21, we get 1 and a remainder of 9.
Record the quotient 1 as the next digit in the result. 
Result so far: 2568212.1428571
If we subtract 21 from 30, we get 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Going ahead to step 16:
If we divide 90 by 21, we get 4 and a remainder of 6.
Put 4 as the next digit of the answer. 
Result so far: 2568212.14285714
The remainder is 6 after subtracting 84 from 90.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

The final result is 2568212.14285714 with a remainder of 6e-09.