We're dividing 52156959 by 21 
Let's see how many times 21 fits into 52156959.

On to step 1:
When dividing 5 by 21, we get 0 with a remainder of 5.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 5 and we're left with 5.
Grab the next digit (2) from the dividend, add it to 5, then carry on: 52 / 21

Going ahead to step 2:
21 can be fit into 52 2 times, resulting in a remainder of 10.
The next digit of our result is 2. 
Result so far: 2.0
If we subtract 42 from 52, we get 10.
Include the next digit (1) from the dividend after 10, then repeat: 101 / 21

Let's proceed to step 3:
21 goes into 101 4 times with a remainder of 17.
Put 4 as the next digit of the answer. 
Result so far: 24.0
If we take 84 away from 101, we end up with 17.
Grab the next digit (5) from the dividend, add it to 17, then carry on: 175 / 21

Advancing to step 4:
The number 21 fits into 175 8 times, leaving a remainder of 7.
The number 8 becomes the next digit in our result. 
Result so far: 248.0
The remainder is 7 after subtracting 168 from 175.
Append the next digit (6) from the dividend to 7 and continue with: 76 / 21

Advancing to step 5:
76 divided by 21 is 3 with a remainder of 13.
Write down 3 as next digit of the result. 
Result so far: 2483.0
Deduct 63 from 76 and we're left with 13.
Grab the next digit (9) from the dividend, add it to 13, then carry on: 139 / 21

Advancing to step 6:
139 divided by 21 is 6 with a remainder of 13.
The number 6 becomes the next digit in our result. 
Result so far: 24836.0
Subtract 126 from 139 to get 13.
Append the next digit (5) from the dividend to 13 and continue with: 135 / 21

Moving on to step 7:
21 goes into 135 6 times with a remainder of 9.
Record the quotient 6 as the next digit in the result. 
Result so far: 248366.0
If we subtract 126 from 135, we get 9.
Append the next digit (9) from the dividend to 9 and continue with: 99 / 21

Step 8:
When dividing 99 by 21, we get 4 with a remainder of 15.
Write down 4 as next digit of the result. 
Result so far: 2483664.0
If we subtract 84 from 99, we get 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 9:
21 can be fit into 150 7 times, resulting in a remainder of 3.
Put 7 as the next digit of the answer. 
Result so far: 2483664.7
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Advancing to step 10:
If we divide 30 by 21, we get 1 and a remainder of 9.
Use 1 as the next digit of our solution. 
Result so far: 2483664.71
The remainder is 9 after subtracting 21 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Let's proceed to step 11:
21 can be fit into 90 4 times, resulting in a remainder of 6.
Record the quotient 4 as the next digit in the result. 
Result so far: 2483664.714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Going ahead to step 12:
When dividing 60 by 21, we get 2 with a remainder of 18.
The next digit of our result is 2. 
Result so far: 2483664.7142
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Moving on to step 13:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 2483664.71428
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.

Let's proceed to step 14:
The number 21 fits into 120 5 times, leaving a remainder of 15.
The next digit of our result is 5. 
Result so far: 2483664.714285
Subtracting 105 from 120 leaves us 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.

Moving on to step 15:
21 goes into 150 7 times with a remainder of 3.
Record the quotient 7 as the next digit in the result. 
Result so far: 2483664.7142857
Subtract 147 from 150 to get 3.
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 16:
If we divide 30 by 21, we get 1 and a remainder of 9.
The number 1 becomes the next digit in our result. 
Result so far: 2483664.71428571
Subtract 21 from 30 to 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.

The final result is 2483664.71428571 with a remainder of 9e-09.