21130786 ÷ 356 
The aim is to understand the frequency of 356 in 21130786.

Let's proceed to step 1:
356 goes into 2 0 times with a remainder of 2.
The next digit of our result is 0. 
Result so far: 0.0
Deduct 0 from 2 and we're left with 2.
Fetch the next digit (1) from the dividend, attach it to 2 and continue: 21 / 356

On to step 2:
The number 356 fits into 21 0 times, leaving a remainder of 21.
The number 0 becomes the next digit in our result. 
Result so far: 0.0
The remainder is 21 after subtracting 0 from 21.
Take the next digit (1) from the dividend and append it to 21, then repeat: 211 / 356

Going ahead to step 3:
211 divided by 356 is 0 with a remainder of 211.
Use 0 as the next digit of our solution. 
Result so far: 0.0
If we subtract 0 from 211, we get 211.
Append the next digit (3) from the dividend to 211 and continue with: 2113 / 356

Going ahead to step 4:
2113 divided by 356 is 5 with a remainder of 333.
Use 5 as the next digit of our solution. 
Result so far: 5.0
If we take 1780 away from 2113, we end up with 333.
Fetch the next digit (0) from the dividend, attach it to 333 and continue: 3330 / 356

Let's proceed to step 5:
356 can be fit into 3330 9 times, resulting in a remainder of 126.
Use 9 as the next digit of our solution. 
Result so far: 59.0
Subtract 3204 from 3330 to get 126.
Take the next digit (7) from the dividend and append it to 126, then repeat: 1267 / 356

On to step 6:
The number 356 fits into 1267 3 times, leaving a remainder of 199.
Put 3 as the next digit of the answer. 
Result so far: 593.0
The remainder is 199 after subtracting 1068 from 1267.
Fetch the next digit (8) from the dividend, attach it to 199 and continue: 1998 / 356

On to step 7:
The number 356 fits into 1998 5 times, leaving a remainder of 218.
Use 5 as the next digit of our solution. 
Result so far: 5935.0
If we subtract 1780 from 1998, we get 218.
Include the next digit (6) from the dividend after 218, then repeat: 2186 / 356

Advancing to step 8:
If we divide 2186 by 356, we get 6 and a remainder of 50.
Put 6 as the next digit of the answer. 
Result so far: 59356.0
Deduct 2136 from 2186 and we're left with 50.
Since there are no more digits in the dividend, we add a zero to the remainder making it 500, and continue the process.

Moving on to step 9:
If we divide 500 by 356, we get 1 and a remainder of 144.
Write down 1 as next digit of the result. 
Result so far: 59356.1
If we subtract 356 from 500, we get 144.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1440, and continue the process.

Going ahead to step 10:
The number 356 fits into 1440 4 times, leaving a remainder of 16.
Record the quotient 4 as the next digit in the result. 
Result so far: 59356.14
The remainder is 16 after subtracting 1424 from 1440.
Since there are no more digits in the dividend, we add a zero to the remainder making it 160, and continue the process.

Going ahead to step 11:
356 can be fit into 160 0 times, resulting in a remainder of 160.
Put 0 as the next digit of the answer. 
Result so far: 59356.14
The remainder is 160 after subtracting 0 from 160.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1600, and continue the process.

Advancing to step 12:
If we divide 1600 by 356, we get 4 and a remainder of 176.
Put 4 as the next digit of the answer. 
Result so far: 59356.1404
If we subtract 1424 from 1600, we get 176.
Since there are no more digits in the dividend, we add a zero to the remainder making it 1760, and continue the process.

Step 13:
356 goes into 1760 4 times with a remainder of 336.
The number 4 becomes the next digit in our result. 
Result so far: 59356.14044
Deduct 1424 from 1760 and we're left with 336.
Since there are no more digits in the dividend, we add a zero to the remainder making it 3360, and continue the process.

The final result is 59356.14044 with a remainder of 0.000336.