621049 ÷ 21 
We're looking to find how many times 21 goes into 621049.

Let's proceed to step 1:
The number 21 fits into 6 0 times, leaving a remainder of 6.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtract 0 from 6 to get 6.
Include the next digit (2) from the dividend after 6, then repeat: 62 / 21

On to step 2:
If we divide 62 by 21, we get 2 and a remainder of 20.
Record the quotient 2 as the next digit in the result. 
Result so far: 2.0
If we take 42 away from 62, we end up with 20.
Include the next digit (1) from the dividend after 20, then repeat: 201 / 21

Going ahead to step 3:
When dividing 201 by 21, we get 9 with a remainder of 12.
Use 9 as the next digit of our solution. 
Result so far: 29.0
If we subtract 189 from 201, we get 12.
Include the next digit (0) from the dividend after 12, then repeat: 120 / 21

Moving on to step 4:
When dividing 120 by 21, we get 5 with a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 295.0
Deduct 105 from 120 and we're left with 15.
Take the next digit (4) from the dividend and append it to 15, then repeat: 154 / 21

On to step 5:
154 divided by 21 is 7 with a remainder of 7.
Write down 7 as next digit of the result. 
Result so far: 2957.0
Deduct 147 from 154 and we're left with 7.
Take the next digit (9) from the dividend and append it to 7, then repeat: 79 / 21

Let's proceed to step 6:
21 can be fit into 79 3 times, resulting in a remainder of 16.
The next digit of our result is 3. 
Result so far: 29573.0
Deduct 63 from 79 and we're left with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Step 7:
If we divide 160 by 21, we get 7 and a remainder of 13.
Put 7 as the next digit of the answer. 
Result so far: 29573.7
Subtracting 147 from 160 leaves us with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Let's proceed to step 8:
130 divided by 21 is 6 with a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 29573.76
Subtracting 126 from 130 leaves us with 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

Advancing to step 9:
40 divided by 21 is 1 with a remainder of 19.
Put 1 as the next digit of the answer. 
Result so far: 29573.761
Deduct 21 from 40 and we're left with 19.
Since there are no more digits in the dividend, we add a zero to the remainder making it 190, and continue the process.

Going ahead to step 10:
When dividing 190 by 21, we get 9 with a remainder of 1.
Record the quotient 9 as the next digit in the result. 
Result so far: 29573.7619
Subtract 189 from 190 to get 1.
Since there are no more digits in the dividend, we add a zero to the remainder making it 10, and continue the process.

Going ahead to step 11:
21 can be fit into 10 0 times, resulting in a remainder of 10.
Use 0 as the next digit of our solution. 
Result so far: 29573.7619
Deduct 0 from 10 and we're left with 10.
Since there are no more digits in the dividend, we add a zero to the remainder making it 100, and continue the process.

Going ahead to step 12:
If we divide 100 by 21, we get 4 and a remainder of 16.
The next digit of our result is 4. 
Result so far: 29573.761904
Subtracting 84 from 100 leaves us with 16.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Advancing to step 13:
The number 21 fits into 160 7 times, leaving a remainder of 13.
The next digit of our result is 7. 
Result so far: 29573.7619047
Deduct 147 from 160 and we're left with 13.
Since there are no more digits in the dividend, we add a zero to the remainder making it 130, and continue the process.

Going ahead to step 14:
The number 21 fits into 130 6 times, leaving a remainder of 4.
Put 6 as the next digit of the answer. 
Result so far: 29573.76190476
If we subtract 126 from 130, we get 4.
Since there are no more digits in the dividend, we add a zero to the remainder making it 40, and continue the process.

The final result is 29573.76190476 with a remainder of 4e-09.