We look at the division of 21309069 by 8 
We want to figure out the number of times 21309069 can be divided by 8.

Moving on to step 1:
8 goes into 2 0 times with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
Subtracting 0 from 2 leaves us with 2.
Include the next digit (1) from the dividend after 2, then repeat: 21 / 8

Step 2:
The number 8 fits into 21 2 times, leaving a remainder of 5.
The next digit of our result is 2. 
Result so far: 2.0
Deduct 16 from 21 and we're left with 5.
Append the next digit (3) from the dividend to 5 and continue with: 53 / 8

Let's proceed to step 3:
The number 8 fits into 53 6 times, leaving a remainder of 5.
Record the quotient 6 as the next digit in the result. 
Result so far: 26.0
Subtract 48 from 53 to get 5.
Include the next digit (0) from the dividend after 5, then repeat: 50 / 8

Step 4:
8 can be fit into 50 6 times, resulting in a remainder of 2.
The number 6 becomes the next digit in our result. 
Result so far: 266.0
Deduct 48 from 50 and we're left with 2.
Bring next digit (9) of the dividend behind the 2 and repeat the process: 29 / 8

Let's proceed to step 5:
29 divided by 8 is 3 with a remainder of 5.
Write down 3 as next digit of the result. 
Result so far: 2663.0
Subtract 24 from 29 to get 5.
Bring next digit (0) of the dividend behind the 5 and repeat the process: 50 / 8

Moving on to step 6:
8 can be fit into 50 6 times, resulting in a remainder of 2.
The next digit of our result is 6. 
Result so far: 26636.0
If we take 48 away from 50, we end up with 2.
Grab the next digit (6) from the dividend, add it to 2, then carry on: 26 / 8

Moving on to step 7:
26 divided by 8 is 3 with a remainder of 2.
The next digit of our result is 3. 
Result so far: 266363.0
Deduct 24 from 26 and we're left with 2.
Append the next digit (9) from the dividend to 2 and continue with: 29 / 8

Step 8:
If we divide 29 by 8, we get 3 and a remainder of 5.
Use 3 as the next digit of our solution. 
Result so far: 2663633.0
The remainder is 5 after subtracting 24 from 29.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 9:
The number 8 fits into 50 6 times, leaving a remainder of 2.
Put 6 as the next digit of the answer. 
Result so far: 2663633.6
If we subtract 48 from 50, we get 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 10:
The number 8 fits into 20 2 times, leaving a remainder of 4.
Put 2 as the next digit of the answer. 
Result so far: 2663633.62
If we take 16 away from 20, we end up 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.

Let's proceed to step 11:
8 can be fit into 40 5 times, resulting in a remainder of 0.
The number 5 becomes the next digit in our result. 
Result so far: 2663633.625
If we take 40 away from 40, 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.

Advancing to step 12:
When dividing 0 by 8, we get 0 with a remainder of 0.
Put 0 as the next digit of the answer. 
Result so far: 2663633.625
Subtract 0 from 0 to 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.

On to step 13:
8 can be fit into 0 0 times, resulting in a remainder of 0.
Use 0 as the next digit of our solution. 
Result so far: 2663633.625
Subtracting 0 from 0 leaves us 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.

The final outcome is 2663633.625, with a leftover of 0.0.