21915215 divided by 755 
We want to figure out the number of times 21915215 can be divided by 755.

Advancing to step 1:
When dividing 2 by 755, we get 0 with a remainder of 2.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we take 0 away from 2, we end up with 2.
Append the next digit (1) from the dividend to 2 and continue with: 21 / 755

On to step 2:
If we divide 21 by 755, we get 0 and a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
If we subtract 0 from 21, we get 21.
Include the next digit (9) from the dividend after 21, then repeat: 219 / 755

Going ahead to step 3:
219 divided by 755 is 0 with a remainder of 219.
The next digit of our result is 0. 
Result so far: 0.0
The remainder is 219 after subtracting 0 from 219.
Bring next digit (1) of the dividend behind the 219 and repeat the process: 2191 / 755

Advancing to step 4:
If we divide 2191 by 755, we get 2 and a remainder of 681.
The number 2 becomes the next digit in our result. 
Result so far: 2.0
Deduct 1510 from 2191 and we're left with 681.
Include the next digit (5) from the dividend after 681, then repeat: 6815 / 755

On to step 5:
The number 755 fits into 6815 9 times, leaving a remainder of 20.
The number 9 becomes the next digit in our result. 
Result so far: 29.0
Deduct 6795 from 6815 and we're left with 20.
Bring next digit (2) of the dividend behind the 20 and repeat the process: 202 / 755

Let's proceed to step 6:
202 divided by 755 is 0 with a remainder of 202.
Use 0 as the next digit of our solution. 
Result so far: 290.0
The remainder is 202 after subtracting 0 from 202.
Include the next digit (1) from the dividend after 202, then repeat: 2021 / 755

Let's proceed to step 7:
If we divide 2021 by 755, we get 2 and a remainder of 511.
Write down 2 as next digit of the result. 
Result so far: 2902.0
If we take 1510 away from 2021, we end up with 511.
Take the next digit (5) from the dividend and append it to 511, then repeat: 5115 / 755

Advancing to step 8:
755 goes into 5115 6 times with a remainder of 585.
The next digit of our result is 6. 
Result so far: 29026.0
If we take 4530 away from 5115, we end up with 585.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5850, and continue the process.

Let's proceed to step 9:
755 goes into 5850 7 times with a remainder of 565.
The next digit of our result is 7. 
Result so far: 29026.7
Subtract 5285 from 5850 to get 565.
Since there are no more digits in the dividend, we add a zero to the remainder making it 5650, and continue the process.

On to step 10:
The number 755 fits into 5650 7 times, leaving a remainder of 365.
Use 7 as the next digit of our solution. 
Result so far: 29026.77
If we subtract 5285 from 5650, we get 365.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3650, and continue the process.

The final outcome is 29026.77, with a leftover of 0.365.