We're dividing 21264391 by 818 
The aim is to understand the frequency of 818 in 21264391.

On to step 1:
If we divide 2 by 818, we get 0 and a remainder of 2.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 2, we get 2.
Take the next digit (1) from the dividend and append it to 2, then repeat: 21 / 818

Step 2:
818 can be fit into 21 0 times, resulting in a remainder of 21.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 21 and we're left with 21.
Take the next digit (2) from the dividend and append it to 21, then repeat: 212 / 818

On to step 3:
818 can be fit into 212 0 times, resulting in a remainder of 212.
Use 0 as the next digit of our solution. 
Result so far: 0.0
Subtracting 0 from 212 leaves us with 212.
Grab the next digit (6) from the dividend, add it to 212, then carry on: 2126 / 818

Step 4:
When dividing 2126 by 818, we get 2 with a remainder of 490.
Write down 2 as next digit of the result. 
Result so far: 2.0
The remainder is 490 after subtracting 1636 from 2126.
Take the next digit (4) from the dividend and append it to 490, then repeat: 4904 / 818

Going ahead to step 5:
If we divide 4904 by 818, we get 5 and a remainder of 814.
Write down 5 as next digit of the result. 
Result so far: 25.0
Subtracting 4090 from 4904 leaves us with 814.
Grab the next digit (3) from the dividend, add it to 814, then carry on: 8143 / 818

Advancing to step 6:
If we divide 8143 by 818, we get 9 and a remainder of 781.
The next digit of our result is 9. 
Result so far: 259.0
Deduct 7362 from 8143 and we're left with 781.
Grab the next digit (9) from the dividend, add it to 781, then carry on: 7819 / 818

On to step 7:
The number 818 fits into 7819 9 times, leaving a remainder of 457.
Record the quotient 9 as the next digit in the result. 
Result so far: 2599.0
The remainder is 457 after subtracting 7362 from 7819.
Bring next digit (1) of the dividend behind the 457 and repeat the process: 4571 / 818

Going ahead to step 8:
818 can be fit into 4571 5 times, resulting in a remainder of 481.
The next digit of our result is 5. 
Result so far: 25995.0
The remainder is 481 after subtracting 4090 from 4571.
Since there are no more digits in the dividend, we add a zero to the remainder making it 4810, and continue the process.

On to step 9:
If we divide 4810 by 818, we get 5 and a remainder of 720.
Use 5 as the next digit of our solution. 
Result so far: 25995.5
Subtract 4090 from 4810 to get 720.
Since there are no more digits in the dividend, we add a zero to the remainder making it 7200, and continue the process.

Step 10:
818 goes into 7200 8 times with a remainder of 656.
Put 8 as the next digit of the answer. 
Result so far: 25995.58
If we subtract 6544 from 7200, we get 656.
Since there are no more digits in the dividend, we add a zero to the remainder making it 6560, and continue the process.

On to step 11:
818 can be fit into 6560 8 times, resulting in a remainder of 16.
Put 8 as the next digit of the answer. 
Result so far: 25995.588
Deduct 6544 from 6560 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.

The quotient of the division is 25995.588, and the remainder is 0.0016.