We look at the division of 421287 by 25 
We're looking to find how many times 25 goes into 421287.

Step 1:
4 divided by 25 is 0 with a remainder of 4.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Subtracting 0 from 4 leaves us with 4.
Grab the next digit (2) from the dividend, add it to 4, then carry on: 42 / 25

Moving on to step 2:
If we divide 42 by 25, we get 1 and a remainder of 17.
Write down 1 as next digit of the result. 
Result so far: 1.0
Deduct 25 from 42 and we're left with 17.
Include the next digit (1) from the dividend after 17, then repeat: 171 / 25

Going ahead to step 3:
When dividing 171 by 25, we get 6 with a remainder of 21.
The next digit of our result is 6. 
Result so far: 16.0
The remainder is 21 after subtracting 150 from 171.
Fetch the next digit (2) from the dividend, attach it to 21 and continue: 212 / 25

Let's proceed to step 4:
If we divide 212 by 25, we get 8 and a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 168.0
The remainder is 12 after subtracting 200 from 212.
Grab the next digit (8) from the dividend, add it to 12, then carry on: 128 / 25

On to step 5:
If we divide 128 by 25, we get 5 and a remainder of 3.
Record the quotient 5 as the next digit in the result. 
Result so far: 1685.0
Deduct 125 from 128 and we're left with 3.
Take the next digit (7) from the dividend and append it to 3, then repeat: 37 / 25

Let's proceed to step 6:
If we divide 37 by 25, we get 1 and a remainder of 12.
The next digit of our result is 1. 
Result so far: 16851.0
Subtract 25 from 37 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.

Advancing to step 7:
If we divide 120 by 25, we get 4 and a remainder of 20.
Record the quotient 4 as the next digit in the result. 
Result so far: 16851.4
If we take 100 away from 120, we end up with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 8:
If we divide 200 by 25, we get 8 and a remainder of 0.
Put 8 as the next digit of the answer. 
Result so far: 16851.48
If we take 200 away from 200, we end up with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

Advancing to step 9:
25 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 16851.48
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

On to step 10:
25 can be fit into 0 0 times, resulting in a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 16851.48
Deduct 0 from 0 and we're left with 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

The quotient of the division is 16851.48, and the remainder is 0.0.