We look at the division of 10189122 by 21 
We want to figure out the number of times 10189122 can be divided by 21.

Let's proceed to step 1:
21 goes into 1 0 times with a remainder of 1.
Put 0 as the next digit of the answer. 
Result so far: 0.0
Deduct 0 from 1 and we're left with 1.
Take the next digit (0) from the dividend and append it to 1, then repeat: 10 / 21

Advancing to step 2:
10 divided by 21 is 0 with a remainder of 10.
Put 0 as the next digit of the answer. 
Result so far: 0.0
The remainder is 10 after subtracting 0 from 10.
Take the next digit (1) from the dividend and append it to 10, then repeat: 101 / 21

Advancing to step 3:
When dividing 101 by 21, we get 4 with a remainder of 17.
The next digit of our result is 4. 
Result so far: 4.0
If we subtract 84 from 101, we get 17.
Fetch the next digit (8) from the dividend, attach it to 17 and continue: 178 / 21

Going ahead to step 4:
When dividing 178 by 21, we get 8 with a remainder of 10.
The number 8 becomes the next digit in our result. 
Result so far: 48.0
Subtract 168 from 178 to get 10.
Bring next digit (9) of the dividend behind the 10 and repeat the process: 109 / 21

Moving on to step 5:
When dividing 109 by 21, we get 5 with a remainder of 4.
Write down 5 as next digit of the result. 
Result so far: 485.0
Subtract 105 from 109 to get 4.
Append the next digit (1) from the dividend to 4 and continue with: 41 / 21

Advancing to step 6:
21 goes into 41 1 times with a remainder of 20.
Put 1 as the next digit of the answer. 
Result so far: 4851.0
Deduct 21 from 41 and we're left with 20.
Append the next digit (2) from the dividend to 20 and continue with: 202 / 21

Going ahead to step 7:
21 can be fit into 202 9 times, resulting in a remainder of 13.
Record the quotient 9 as the next digit in the result. 
Result so far: 48519.0
Deduct 189 from 202 and we're left with 13.
Take the next digit (2) from the dividend and append it to 13, then repeat: 132 / 21

Let's proceed to step 8:
If we divide 132 by 21, we get 6 and a remainder of 6.
Write down 6 as next digit of the result. 
Result so far: 485196.0
The remainder is 6 after subtracting 126 from 132.
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 9:
When dividing 60 by 21, we get 2 with a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 485196.2
Deduct 42 from 60 and we're left with 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 10:
21 can be fit into 180 8 times, resulting in a remainder of 12.
Use 8 as the next digit of our solution. 
Result so far: 485196.28
If we subtract 168 from 180, we 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.

Let's proceed to step 11:
The number 21 fits into 120 5 times, leaving a remainder of 15.
Use 5 as the next digit of our solution. 
Result so far: 485196.285
If we subtract 105 from 120, we get 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 12:
When dividing 150 by 21, we get 7 with a remainder of 3.
The next digit of our result is 7. 
Result so far: 485196.2857
Deduct 147 from 150 and we're left 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.

On to step 13:
The number 21 fits into 30 1 times, leaving a remainder of 9.
Put 1 as the next digit of the answer. 
Result so far: 485196.28571
The remainder is 9 after subtracting 21 from 30.
Since there are no more digits in the dividend, we add a zero to the remainder making it 90, and continue the process.

Advancing to step 14:
If we divide 90 by 21, we get 4 and a remainder of 6.
Write down 4 as next digit of the result. 
Result so far: 485196.285714
If we subtract 84 from 90, we 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 15:
The number 21 fits into 60 2 times, leaving a remainder of 18.
The number 2 becomes the next digit in our result. 
Result so far: 485196.2857142
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.

Moving on to step 16:
The number 21 fits into 180 8 times, leaving a remainder of 12.
Write down 8 as next digit of the result. 
Result so far: 485196.28571428
Deduct 168 from 180 and we're left 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 outcome is 485196.28571428, with a leftover of 1.2e-08.