We divide 426237 by 21
We want to figure out the number of times 426237 can be divided by 21.

Step 1:
4 divided by 21 is 0 with a remainder of 4.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we take 0 away from 4, we end up with 4.
Bring next digit (2) of the dividend behind the 4 and repeat the process: 42 / 21

Moving on to step 2:
The number 21 fits into 42 2 times, leaving a remainder of 0.
Put 2 as the next digit of the answer. 
Result so far: 2.0
If we subtract 42 from 42, we get 0.
Take the next digit (6) from the dividend and append it to 0, then repeat: 6 / 21

Advancing to step 3:
If we divide 6 by 21, we get 0 and a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 20.0
Subtracting 0 from 6 leaves us with 6.
Grab the next digit (2) from the dividend, add it to 6, then carry on: 62 / 21

On to step 4:
If we divide 62 by 21, we get 2 and a remainder of 20.
Write down 2 as next digit of the result. 
Result so far: 202.0
Subtract 42 from 62 to get 20.
Fetch the next digit (3) from the dividend, attach it to 20 and continue: 203 / 21

Moving on to step 5:
The number 21 fits into 203 9 times, leaving a remainder of 14.
Put 9 as the next digit of the answer. 
Result so far: 2029.0
If we subtract 189 from 203, we get 14.
Grab the next digit (7) from the dividend, add it to 14, then carry on: 147 / 21

Moving on to step 6:
147 divided by 21 is 7 with a remainder of 0.
Write down 7 as next digit of the result. 
Result so far: 20297.0
If we take 147 away from 147, 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.

Let's proceed to step 7:
The number 21 fits into 0 0 times, leaving a remainder of 0.
The next digit of our result is 0. 
Result so far: 20297.0
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.

Moving on to step 8:
0 divided by 21 is 0 with a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 20297.0
If we subtract 0 from 0, we get 0.
Since there are no more digits in the dividend, we add a zero to the remainder making it 0, and continue the process.

After the division, we end up with 20297.0 and a remainder of 0.0.