We look at the division of 7321089 by 21 
Let's see how many times 21 fits into 7321089.

Let's proceed to step 1:
When dividing 7 by 21, we get 0 with a remainder of 7.
The next digit of our result is 0. 
Result so far: 0.0
Subtract 0 from 7 to get 7.
Append the next digit (3) from the dividend to 7 and continue with: 73 / 21

Going ahead to step 2:
21 goes into 73 3 times with a remainder of 10.
Use 3 as the next digit of our solution. 
Result so far: 3.0
Subtracting 63 from 73 leaves us with 10.
Bring next digit (2) of the dividend behind the 10 and repeat the process: 102 / 21

Advancing to step 3:
21 can be fit into 102 4 times, resulting in a remainder of 18.
Write down 4 as next digit of the result. 
Result so far: 34.0
The remainder is 18 after subtracting 84 from 102.
Grab the next digit (1) from the dividend, add it to 18, then carry on: 181 / 21

On to step 4:
If we divide 181 by 21, we get 8 and a remainder of 13.
The number 8 becomes the next digit in our result. 
Result so far: 348.0
If we subtract 168 from 181, we get 13.
Grab the next digit (0) from the dividend, add it to 13, then carry on: 130 / 21

Let's proceed to step 5:
21 goes into 130 6 times with a remainder of 4.
Use 6 as the next digit of our solution. 
Result so far: 3486.0
If we subtract 126 from 130, we get 4.
Fetch the next digit (8) from the dividend, attach it to 4 and continue: 48 / 21

Step 6:
48 divided by 21 is 2 with a remainder of 6.
The next digit of our result is 2. 
Result so far: 34862.0
Subtract 42 from 48 to get 6.
Bring next digit (9) of the dividend behind the 6 and repeat the process: 69 / 21

Going ahead to step 7:
When dividing 69 by 21, we get 3 with a remainder of 6.
Record the quotient 3 as the next digit in the result. 
Result so far: 348623.0
Subtract 63 from 69 to get 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

On to step 8:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The next digit of our result is 2. 
Result so far: 348623.2
Subtract 42 from 60 to get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Let's proceed to step 9:
If we divide 180 by 21, we get 8 and a remainder of 12.
Put 8 as the next digit of the answer. 
Result so far: 348623.28
Subtract 168 from 180 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.

Going ahead to step 10:
When dividing 120 by 21, we get 5 with a remainder of 15.
Put 5 as the next digit of the answer. 
Result so far: 348623.285
If we take 105 away from 120, we end up with 15.
Since there are no more digits in the dividend, we add a zero to the remainder making it 150, and continue the process.

Advancing to step 11:
150 divided by 21 is 7 with a remainder of 3.
Use 7 as the next digit of our solution. 
Result so far: 348623.2857
If we take 147 away from 150, we end up with 3.
Since there are no more digits in the dividend, we add a zero to the remainder making it 30, and continue the process.

Step 12:
The number 21 fits into 30 1 times, leaving a remainder of 9.
The next digit of our result is 1. 
Result so far: 348623.28571
If we take 21 away from 30, we end up with 9.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Moving on to step 13:
21 can be fit into 90 4 times, resulting in a remainder of 6.
The next digit of our result is 4. 
Result so far: 348623.285714
If we take 84 away from 90, we end up with 6.
Since there are no more digits in the dividend, we add a zero to the remainder making it 60, and continue the process.

Advancing to step 14:
If we divide 60 by 21, we get 2 and a remainder of 18.
The next digit of our result is 2. 
Result so far: 348623.2857142
If we subtract 42 from 60, we get 18.
Since there are no more digits in the dividend, we add a zero to the remainder making it 180, and continue the process.

Step 15:
180 divided by 21 is 8 with a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 348623.28571428
Subtracting 168 from 180 leaves us with 12.
Since there are no more digits in the dividend, we add a zero to the remainder making it 120, and continue the process.

The final result is 348623.28571428 with a remainder of 1.2e-08.