1315316 ÷ 21 
The aim is to understand the frequency of 21 in 1315316.

Advancing to step 1:
21 can be fit into 1 0 times, resulting in a remainder of 1.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
If we subtract 0 from 1, we get 1.
Fetch the next digit (3) from the dividend, attach it to 1 and continue: 13 / 21

Moving on to step 2:
13 divided by 21 is 0 with a remainder of 13.
Put 0 as the next digit of the answer. 
Result so far: 0.0
If we subtract 0 from 13, we get 13.
Grab the next digit (1) from the dividend, add it to 13, then carry on: 131 / 21

On to step 3:
131 divided by 21 is 6 with a remainder of 5.
Put 6 as the next digit of the answer. 
Result so far: 6.0
If we subtract 126 from 131, we get 5.
Take the next digit (5) from the dividend and append it to 5, then repeat: 55 / 21

On to step 4:
55 divided by 21 is 2 with a remainder of 13.
Use 2 as the next digit of our solution. 
Result so far: 62.0
The remainder is 13 after subtracting 42 from 55.
Grab the next digit (3) from the dividend, add it to 13, then carry on: 133 / 21

Advancing to step 5:
If we divide 133 by 21, we get 6 and a remainder of 7.
The number 6 becomes the next digit in our result. 
Result so far: 626.0
The remainder is 7 after subtracting 126 from 133.
Bring next digit (1) of the dividend behind the 7 and repeat the process: 71 / 21

On to step 6:
If we divide 71 by 21, we get 3 and a remainder of 8.
Write down 3 as next digit of the result. 
Result so far: 6263.0
Subtract 63 from 71 to get 8.
Include the next digit (6) from the dividend after 8, then repeat: 86 / 21

Advancing to step 7:
The number 21 fits into 86 4 times, leaving a remainder of 2.
Use 4 as the next digit of our solution. 
Result so far: 62634.0
The remainder is 2 after subtracting 84 from 86.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Advancing to step 8:
20 divided by 21 is 0 with a remainder of 20.
Write down 0 as next digit of the result. 
Result so far: 62634.0
Deduct 0 from 20 and we're left with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Going ahead to step 9:
If we divide 200 by 21, we get 9 and a remainder of 11.
The number 9 becomes the next digit in our result. 
Result so far: 62634.09
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

Moving on to step 10:
21 goes into 110 5 times with a remainder of 5.
Put 5 as the next digit of the answer. 
Result so far: 62634.095
Subtracting 105 from 110 leaves us with 5.
Since there are no more digits in the dividend, we add a zero to the remainder making it 50, and continue the process.

Step 11:
When dividing 50 by 21, we get 2 with a remainder of 8.
Put 2 as the next digit of the answer. 
Result so far: 62634.0952
Subtract 42 from 50 to get 8.
Since there are no more digits in the dividend, we add a zero to the remainder making it 80, and continue the process.

Step 12:
When dividing 80 by 21, we get 3 with a remainder of 17.
The number 3 becomes the next digit in our result. 
Result so far: 62634.09523
The remainder is 17 after subtracting 63 from 80.
Since there are no more digits in the dividend, we add a zero to the remainder making it 170, and continue the process.

Advancing to step 13:
The number 21 fits into 170 8 times, leaving a remainder of 2.
The number 8 becomes the next digit in our result. 
Result so far: 62634.095238
If we take 168 away from 170, we end up with 2.
Since there are no more digits in the dividend, we add a zero to the remainder making it 20, and continue the process.

Going ahead to step 14:
If we divide 20 by 21, we get 0 and a remainder of 20.
Use 0 as the next digit of our solution. 
Result so far: 62634.095238
Subtracting 0 from 20 leaves us with 20.
Since there are no more digits in the dividend, we add a zero to the remainder making it 200, and continue the process.

Moving on to step 15:
21 goes into 200 9 times with a remainder of 11.
Record the quotient 9 as the next digit in the result. 
Result so far: 62634.09523809
The remainder is 11 after subtracting 189 from 200.
Since there are no more digits in the dividend, we add a zero to the remainder making it 110, and continue the process.

The final outcome is 62634.09523809, with a leftover of 1.1e-08.