125902 divided by 21 
We want to figure out the number of times 125902 can be divided by 21.

Going ahead to step 1:
21 goes into 1 0 times with a remainder of 1.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Fetch the next digit (2) from the dividend, attach it to 1 and continue: 12 / 21

Advancing to step 2:
When dividing 12 by 21, we get 0 with a remainder of 12.
Record the quotient 0 as the next digit in the result. 
Result so far: 0.0
The remainder is 12 after subtracting 0 from 12.
Fetch the next digit (5) from the dividend, attach it to 12 and continue: 125 / 21

Let's proceed to step 3:
When dividing 125 by 21, we get 5 with a remainder of 20.
The number 5 becomes the next digit in our result. 
Result so far: 5.0
The remainder is 20 after subtracting 105 from 125.
Include the next digit (9) from the dividend after 20, then repeat: 209 / 21

On to step 4:
When dividing 209 by 21, we get 9 with a remainder of 20.
The number 9 becomes the next digit in our result. 
Result so far: 59.0
Subtracting 189 from 209 leaves us with 20.
Grab the next digit (0) from the dividend, add it to 20, then carry on: 200 / 21

Moving on to step 5:
21 can be fit into 200 9 times, resulting in a remainder of 11.
Put 9 as the next digit of the answer. 
Result so far: 599.0
If we take 189 away from 200, we end up with 11.
Grab the next digit (2) from the dividend, add it to 11, then carry on: 112 / 21

On to step 6:
21 goes into 112 5 times with a remainder of 7.
Put 5 as the next digit of the answer. 
Result so far: 5995.0
Subtracting 105 from 112 leaves us with 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Let's proceed to step 7:
If we divide 70 by 21, we get 3 and a remainder of 7.
The next digit of our result is 3. 
Result so far: 5995.3
The remainder is 7 after subtracting 63 from 70.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

Step 8:
21 can be fit into 70 3 times, resulting in a remainder of 7.
The number 3 becomes the next digit in our result. 
Result so far: 5995.33
If we subtract 63 from 70, we get 7.
Since there are no more digits in the dividend, we add a zero to the remainder making it 70, and continue the process.

In conclusion, the division gives 5995.33 with a balance of 0.007.