We look at the division of 898643 by 21 
We're looking to find how many times 21 goes into 898643.

Step 1:
21 goes into 8 0 times with a remainder of 8.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 8, we get 8.
Include the next digit (9) from the dividend after 8, then repeat: 89 / 21

Going ahead to step 2:
When dividing 89 by 21, we get 4 with a remainder of 5.
The next digit of our result is 4. 
Result so far: 4.0
If we subtract 84 from 89, we get 5.
Include the next digit (8) from the dividend after 5, then repeat: 58 / 21

Step 3:
The number 21 fits into 58 2 times, leaving a remainder of 16.
The next digit of our result is 2. 
Result so far: 42.0
If we take 42 away from 58, we end up with 16.
Take the next digit (6) from the dividend and append it to 16, then repeat: 166 / 21

On to step 4:
166 divided by 21 is 7 with a remainder of 19.
Record the quotient 7 as the next digit in the result. 
Result so far: 427.0
Subtract 147 from 166 to get 19.
Include the next digit (4) from the dividend after 19, then repeat: 194 / 21

Moving on to step 5:
When dividing 194 by 21, we get 9 with a remainder of 5.
Put 9 as the next digit of the answer. 
Result so far: 4279.0
Subtracting 189 from 194 leaves us with 5.
Grab the next digit (3) from the dividend, add it to 5, then carry on: 53 / 21

Step 6:
53 divided by 21 is 2 with a remainder of 11.
Write down 2 as next digit of the result. 
Result so far: 42792.0
Deduct 42 from 53 and we're left with 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

On to step 7:
If we divide 110 by 21, we get 5 and a remainder of 5.
Write down 5 as next digit of the result. 
Result so far: 42792.5
If we take 105 away from 110, we end up with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Let's proceed to step 8:
21 can be fit into 50 2 times, resulting in a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 42792.52
The remainder is 8 after subtracting 42 from 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Going ahead to step 9:
21 can be fit into 80 3 times, resulting in a remainder of 17.
Put 3 as the next digit of the answer. 
Result so far: 42792.523
If we subtract 63 from 80, we get 17.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Moving on to step 10:
21 goes into 170 8 times with a remainder of 2.
Record the quotient 8 as the next digit in the result. 
Result so far: 42792.5238
Deduct 168 from 170 and we're left with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Let's proceed to step 11:
The number 21 fits into 20 0 times, leaving a remainder of 20.
The next digit of our result is 0. 
Result so far: 42792.5238
The remainder is 20 after subtracting 0 from 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 12:
The number 21 fits into 200 9 times, leaving a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 42792.523809
Subtract 189 from 200 to get 11.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 13:
110 divided by 21 is 5 with a remainder of 5.
Use 5 as the next digit of our solution. 
Result so far: 42792.5238095
The remainder is 5 after subtracting 105 from 110.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Advancing to step 14:
The number 21 fits into 50 2 times, leaving a remainder of 8.
Write down 2 as next digit of the result. 
Result so far: 42792.52380952
If we take 42 away from 50, we end up with 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

After the division, we end up with 42792.52380952 and a remainder of 8e-09.